[ { "id": "authors:c9qp3-j8k34", "collection": "authors", "collection_id": "c9qp3-j8k34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIieeetmtt01", "type": "article", "title": "Comments on \"Electric current and electric field induced in a human body when exposed to an incident electric field near the resonant frequency\"", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "King", "given_name": "Ronald W. P.", "clpid": "King-R-W-P" } ], "abstract": "[For original paper see R. W. P. King, IEEE Trans. Microwave Theory Tech., vol. 48, no. 9, pp. 147-53 (2000).] The author makes two observations on the original article. The commentator questions whether a seated person is well modeled as a right circular cylinder. The second observation is that King cites only microwave studies on mice to show that electromagnetic radiation causes malignancies. These studies themselves are widely disputed. He then uses simple dimensional scaling to show that 2.45 GHz for a mouse scales to 100 MHz for a man. Such a scaling law may be useful in calculating the resonant frequency for a human subject versus a mouse when treated as antennas, but such scaling is meaningless when the physics of a hypothetical carcinogenic process are unknown.", "doi": "10.1109/22.915455", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "2001-04", "series_number": "4", "volume": "49", "issue": "4", "pages": "736-737" }, { "id": "authors:xd9tm-d6b47", "collection": "authors", "collection_id": "xd9tm-d6b47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIieeejstqe00", "type": "article", "title": "Ion lasers-the early years", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "The paper is a personal, anecdotal history of the discovery and early development of ion lasers, particularly the argon ion laser. A brief discussion of the mechanisms that make this laser work, and the engineering challenges and developments that make it practical are included. Some early applications in night reconnaissance and imaging are included", "doi": "10.1109/2944.902139", "issn": "1077-260X", "publisher": "IEEE", "publication": "IEEE Journal on Selected Topics in Quantum Electronics", "publication_date": "2000-11", "series_number": "6", "volume": "6", "issue": "6", "pages": "885-898" }, { "id": "authors:p613g-8r841", "collection": "authors", "collection_id": "p613g-8r841", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:CUMjlt98", "type": "article", "title": "Bandwidth of linearized electrooptic modulators", "author": [ { "family_name": "Cummings", "given_name": "Uri V.", "clpid": "Cummings-U-V" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Many schemes have been proposed to make high dynamic range analog radio frequency (RF) photonic links by linearizing the transfer function of the link's modulator. This paper studies the degrading effects of finite transit time and optical and electrical velocity dispersion on such linearization schemes. It further demonstrates that much of the lost dynamic range in some modulators may be regained by segmenting and rephasing the RF transmission line.", "doi": "10.1109/50.704614", "issn": "0733-8724", "publisher": "IEEE", "publication": "Journal of Lightwave Technology", "publication_date": "1998-08", "series_number": "8", "volume": "16", "issue": "8", "pages": "1482-1490" }, { "id": "authors:jnghm-w3n28", "collection": "authors", "collection_id": "jnghm-w3n28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIieeetmtt95", "type": "article", "title": "Distortion in linearized electrooptic modulators", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Schaffner", "given_name": "James H.", "clpid": "Schaffner-J-H" } ], "abstract": "Intermodulation and harmonic distortion are calculated for a simple fiber-optic link with a representative set of link parameters and a variety of electrooptic modulators: simple Mach-Zehnder, linearized dual and triple Mach-Zehnder, simple directional coupler (two operating points), and linearized directional coupler with one and two dc electrodes. The resulting dynamic ranges, gains, and noise figures are compared for these modulators. A new definition of dynamic range is proposed to accommodate the more complicated variation of intermodulation with input power exhibited by linearized modulators. The effects of noise bandwidth, preamplifier distortion, and errors in modulator operating conditions are described.", "doi": "10.1109/22.414563", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "1995-09", "series_number": "9", "volume": "43", "issue": "9", "pages": "2184-2197" }, { "id": "authors:kay7b-ac133", "collection": "authors", "collection_id": "kay7b-ac133", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-145702305", "type": "article", "title": "Powder core dielectric channel waveguide", "author": [ { "family_name": "Bruno", "given_name": "William M.", "clpid": "Bruno-W-M" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "A powder-filled rectangular groove in the surface of a plastic substrate has been demonstrated as a dielectric waveguide at 94 GHz. Propagation losses as low as 0.09 dB/cm were measured by direct transmission with nickel-aluminum titanate powder in a polypropylene substrate and with barium tetratitanate powder in a polytetrafluoroethylene (PTFE) substrate; values as low as 0.06 dB/cm were deduced from ring resonator measurements. Guide wavelengths measured for various combinations of guide dimensions, powders, and substrates agree within 10% with values predicted by the approximate theory of Marcatili for the E/sub 11//sup y/ mode. Effective loss tangents for the powders at 94 GHz were calculated from waveguide attenuation measurements, using Marcatili's field solutions. Ring resonators fabricated by filling a groove in a polypropylene substrate with nickel-aluminum titanate powder exhibit Q's as high as 2400 at 94 GHz in an 8 cm diameter ring. Coupling to the resonators was achieved with adjacent straight powder core channel guides as directional couplers.", "doi": "10.1109/22.297815", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "1994-08", "series_number": "8", "volume": "42", "issue": "8", "pages": "1524-1532" }, { "id": "authors:7wdwv-xfc78", "collection": "authors", "collection_id": "7wdwv-xfc78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:ZHAieeejqe94", "type": "article", "title": "Transverse mode control and switching in gas laser arrays", "author": [ { "family_name": "Zhang", "given_name": "Yongfang", "clpid": "Zhang-Yongfang" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Theoretical and experimental investigations of multiple transverse mode laser oscillation involving spatially varying gain and loss are carried out. The effect of gain and loss distribution on mode competition is analyzed. Numerical examples are given for a CO2 waveguide laser array. Experimental results of CO2 laser arrays are found to be consistent with the theory, and robust in-phase coupled mode array operation has been achieved.", "doi": "10.1109/3.283772", "issn": "0018-9197", "publisher": "IEEE Journal of Quantum Electronics", "publication": "IEEE Journal of Quantum Electronics", "publication_date": "1994-02", "series_number": "2", "volume": "30", "issue": "2", "pages": "284-294" }, { "id": "authors:aekdy-wc480", "collection": "authors", "collection_id": "aekdy-wc480", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:SHEieeeptl93", "type": "article", "title": "60 GHz and 94 GHz antenna-coupled LiNbO_3 electrooptic modulators", "author": [ { "family_name": "Sheehy", "given_name": "Finbar T.", "clpid": "Sheehy-F-T" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Schaffner", "given_name": "James H.", "clpid": "Schaffner-J-H" } ], "abstract": "Antenna-coupled LiBbO_3 electrooptic modulators can overcome the material dispersion which would otherwise prevent sensitive high-frequency operation. The authors previously demonstrated the concept with a phase modulator at X-band. They have extended this demonstration to a narrowband 60-GHz phase modulator and broadband amplitude modulator designs at 60 and 94 GHz, respectively.", "doi": "10.1109/68.205620", "issn": "1041-1135", "publisher": "IEEE", "publication": "IEEE Photonics Technology Letters", "publication_date": "1993-03", "series_number": "3", "volume": "5", "issue": "3", "pages": "307-310" }, { "id": "authors:wcfs2-c5747", "collection": "authors", "collection_id": "wcfs2-c5747", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:SCHAjlt93", "type": "article", "title": "Intermodulation distortion in high dynamic range microwave fiber-optic links with linearized modulators", "author": [ { "family_name": "Schaffner", "given_name": "James H.", "clpid": "Schaffner-J-H" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Linearization of integrated optic intensity modulators significantly reduces the two-tone intermodulation distortion. The resulting intermodulation distortion produced by these modulators then varies as the input power to the fifth-order link system, the overall intermodulation product is a combination of third-order and higher-order terms. The authors determine the dynamic range of a cascaded microwave network consisting of a preamplifier, a high-dynamic-range fiber-optic link with a highly linear modulator, and a postamplifier. An expression is found that relates the intermodulation power at the output to the relative suppression from the signal level. As an example, a hypothetical 10-GHz low-distortion fiber-optic link that has a dynamic range of 125 dB in a bandwidth of 1 Hz is cascaded with various preamplifiers, and it is shown that the dynamic range of the system is reduced by as much as 20 dB, depending on the third-order intercept of the amplifier.", "doi": "10.1109/50.210563", "issn": "0733-8724", "publisher": "Journal of Lightwave Technology", "publication": "Journal of Lightwave Technology", "publication_date": "1993-01-01", "series_number": "1", "volume": "11", "issue": "1", "pages": "3-6" }, { "id": "authors:dypdb-afv49", "collection": "authors", "collection_id": "dypdb-afv49", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIieeeptl91", "type": "article", "title": "Wave-coupled LiNbO_3 electrooptic modulator for microwave and millimeter-wave modulation", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Sheehy", "given_name": "Finbar T.", "clpid": "Sheehy-F-T" }, { "family_name": "Schaffner", "given_name": "J. H.", "clpid": "Schaffner-J-H" } ], "abstract": "A new technique of phase velocity matching in electrooptic modulators was demonstrated. The results show that the phase velocity mismatch due to material dispersion in traveling-wave LiNbO_3 optical waveguide modulators can be greatly reduced by breaking the modulation transmission line into short segments and connecting each segment to its own surface dipole antenna. The array of antennas is then illuminated by the modulation signal from below at the proper angle to produce a delay from antenna to antenna that matches the optical waveguide's delay. A phase modulator 25 mm in length with five antennas and five transmission line segments was operated from 4.6 to 13 GHz with a maximum phase modulation sensitivity of over 100\u00b0/W^(1/2).", "doi": "10.1109/68.76865", "issn": "1041-1135", "publisher": "IEEE", "publication": "IEEE Photonics Technology Letters", "publication_date": "1991-02", "series_number": "2", "volume": "3", "issue": "2", "pages": "133-135" }, { "id": "authors:34dkh-wex17", "collection": "authors", "collection_id": "34dkh-wex17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:ZARel88", "type": "article", "title": "Generation of 1180 \u00c5 period gratings with a Xe ion laser", "author": [ { "family_name": "Zarem", "given_name": "H. A.", "clpid": "Zarem-H-A" }, { "family_name": "Hoenk", "given_name": "M. E.", "clpid": "Hoenk-M-E" }, { "family_name": "Bridges", "given_name": "W. B.", "clpid": "Bridges-W-B" }, { "family_name": "Vahala", "given_name": "K.", "orcid": "0000-0003-1783-1380", "clpid": "Vahala-K-J" }, { "family_name": "Yariv", "given_name": "A.", "clpid": "Yariv-A" } ], "abstract": "Holographic lithography with the 2315 \u00c5 line of a xenon ion laser is used to produce gratings in polymethylmethacrylate. An 1180 \u00c5 period grating is made and examined with a scanning electron microscope (SEM). This grating period is appropriate for use as a first-order grating with a GaAs distributed feedback laser.", "issn": "0013-5194", "publisher": "Electronics Letters", "publication": "Electronics Letters", "publication_date": "1988-10-27", "series_number": "22", "volume": "24", "issue": "22", "pages": "1366-1367" }, { "id": "authors:w0t42-fr748", "collection": "authors", "collection_id": "w0t42-fr748", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRUieeetmtt88", "type": "article", "title": "Flexible dielectric waveguides with powder cores", "author": [ { "family_name": "Bruno", "given_name": "William M.", "clpid": "Bruno-W-M" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Flexible dielectric waveguides have been demonstrated at 10 GHz and 94 GHz using thin-wall polymer tubing filled with low-loss, high-dielectric-constant powders. Absorptive losses of the order of 10 dB/m were measured at 94 GHz. with nickel-aluminium titanate and barium tetratitanate powder in polytetrafluoroethylene (PTFE) lightweight electrical tubing. Bending losses at 94 GHz were negligible for curvature radii greater than 4 cm. M.H. Kuhn's (1974) theory of three-region cylindrical dielectric waveguide was used to calculate dispersion curves for the lower-order modes for several combinations of dimensions and dielectric constants. Good agreement was obtained between experimental and theoretical values of guide wavelength. A scheme is proposed for classifying hybrid modes of three-region guides based on the ratio |Ez/Hz|. For two-region guides, this reduces to E. Snitzer's (1961) familiar scheme.", "doi": "10.1109/22.3608", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "1988-05", "series_number": "5", "volume": "36", "issue": "5", "pages": "882-890" }, { "id": "authors:6869f-1bn71", "collection": "authors", "collection_id": "6869f-1bn71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:NEWapl86", "type": "article", "title": "High power coupled CO2 waveguide laser array", "author": [ { "family_name": "Newman", "given_name": "L. A.", "clpid": "Newman-L-A" }, { "family_name": "Hart", "given_name": "R. A.", "clpid": "Hart-R-A" }, { "family_name": "Kennedy", "given_name": "J. T.", "clpid": "Kennedy-J-T" }, { "family_name": "Cantor", "given_name": "A. J.", "clpid": "Cantor-A-J" }, { "family_name": "DeMaria", "given_name": "A. J.", "clpid": "DeMaria-A-J" }, { "family_name": "Bridges", "given_name": "W. B.", "clpid": "Bridges-W-B" } ], "abstract": "A hollow-bore ridge waveguide technique for phase locking arrays of coupled CO2 rf excited waveguide lasers was demonstrated. Stable phase-locked operation of two- and three-channel arrays has been demonstrated at the 50 W output level. Preliminary experiments with a five-element array generated an output power of 95 W but phase-locked operation was not conclusively demonstrated.", "doi": "10.1063/1.96808", "issn": "0003-6951", "publisher": "Applied Physics Letters", "publication": "Applied Physics Letters", "publication_date": "1986-06-23", "series_number": "25", "volume": "48", "issue": "25", "pages": "1701-1703" }, { "id": "authors:xcs7y-nww90", "collection": "authors", "collection_id": "xcs7y-nww90", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120702-090305339", "type": "article", "title": "Powder Core Dielectric Waveguides", "author": [ { "family_name": "Bruno", "given_name": "William M.", "clpid": "Bruno-W-M" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "A powder-filled surface of a led groove in the teflon substrate has been demonstrated as a dielectric waveguide at 94 GHz. Guide wavelengths measured for combinations of guide dimensions and powders agree within 10% of values predicted by Marcatili 's approximate theory. Attenuation constants of 0.2 to 0.3 dB/cm were measured for barium tetra-titanate.", "doi": "10.1109/MWSYM.1984.1131839", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "1984-08", "series_number": "8", "volume": "42", "issue": "8", "pages": "1524-1532" }, { "id": "authors:pby2p-ykj52", "collection": "authors", "collection_id": "pby2p-ykj52", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:SCHWieeetmtt84", "type": "article", "title": "Computer Analysis of Dielectric Waveguides: A Finite-Difference Method", "author": [ { "family_name": "Schweig", "given_name": "Edgard", "clpid": "Schweig-E" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "A method for computing the modes of dielectric guiding structures based on finite differences is described. The numerical computation program is efficient and can be applied to a wide range of problems. We report here solutions for circular and rectangular dielectric waveguides and compare our solutions with those obtained by other methods. Limitations in the commonly used approximate formulas developed by Marcatili are discussed.", "doi": "10.1109/TMTT.1984.1132717", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "1984-05", "series_number": "5", "volume": "32", "issue": "5", "pages": "531-541" }, { "id": "authors:6fs9j-zxb80", "collection": "authors", "collection_id": "6fs9j-zxb80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIieeetmtt82", "type": "article", "title": "Measurement of the Dielectric Constant and Loss Tangent of Thallium Mixed Halide Crystals KRS-5 and KRS-6 at 95 GHz", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Klein", "given_name": "Marvin B.", "clpid": "Klein-M-B" }, { "family_name": "Schweig", "given_name": "Edgard", "clpid": "Schweig-E" } ], "abstract": "The dielectric constants and loss tangents of KRS-5 and KRS-6 thallium halide mixed crystals have been measured at 95 GHz using both the shorted waveguide (SWG) reflection method and the Fabry-Perot (F-P) transmission method on samples filling standard WR-10 waveguide. The results--KRS-5: epsilon'/sub r/ = 31; tan delta = 1.8 x 10/sup -2/; KRS-6: epsilon'/sub r/ = 29, tan delta = 2 x 10/sup-2/-- agree reasonably well with a simple theoretical fit to the far-infrared Iattice absorption of TIBr and TICI centered at about 1400 GHz. The dielectric samples were hot-pressed into copper wafers with dimensions matching WR-10 waveguide, and then machined and polished to obtain flat, parallel air-dielectric interfaces.", "doi": "10.1109/TMTT.1982.1131063", "issn": "0018-9480", "publisher": "IEEE", "publication": "IEEE Transactions on Microwave Theory and Techniques", "publication_date": "1982-03", "series_number": "3", "volume": "30", "issue": "3", "pages": "286-292" }, { "id": "authors:t0cz8-kae23", "collection": "authors", "collection_id": "t0cz8-kae23", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIao75", "type": "article", "title": "Divergence of high order Gaussian modes", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "A simple expression for the beam divergence from a laser oscillating in a high order Gaussian mode can be derived from the properties of the mathematical expressions for these modes.", "issn": "0003-6935", "publisher": "Optical Society of America", "publication": "Applied Optics", "publication_date": "1975-10", "series_number": "10", "volume": "14", "issue": "10", "pages": "2346-2347" }, { "id": "authors:s7cbf-k5848", "collection": "authors", "collection_id": "s7cbf-k5848", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIapl75", "type": "article", "title": "Thermal blooming compensation using coherent optical adaptive techniques (COAT)", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Pearson", "given_name": "James E.", "clpid": "Pearson-J-E" } ], "abstract": "Real-time compensation for thermally induced beam distortion has been demonstrated using a phase-adaptive aperture subdivided into 18 elements coupled with an 18-channel multidither servo system. The results were obtained using an argon ion laser and a nonlinear liquid cell placed in the near field of the transmitted beam. The system increased the peak beam irradiance by more than a factor of 4 at the highest power used and reduced the beamwidth by a factor of 5.4 from the uncorrected bloomed case. A comparison with predictions from existing theory is given.", "doi": "10.1063/1.88248", "issn": "0003-6951", "publisher": "Applied Physics Letters", "publication": "Applied Physics Letters", "publication_date": "1975-05-01", "series_number": "9", "volume": "26", "issue": "9", "pages": "539-543" }, { "id": "authors:reme2-etv67", "collection": "authors", "collection_id": "reme2-etv67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190312-101304386", "type": "article", "title": "Characteristics of sealed-off waveguide CO_2 lasers", "author": [ { "family_name": "Abrams", "given_name": "Richard L.", "clpid": "Abrams-R-L" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Gain and output power of sealed-off waveguide CO_2 lasers are presented as a function of gas mixtures and total gas pressure. Experimental data on circular-bore and square-channel waveguide lasers are presented. Output power per unit length of 0.2 W/cm is achieved for both types of lasers in agreement with gas-discharge scaling laws which are presented. Saturation intensities as high as 24 kW/cm^2 are inferred from the data. The effects of the optical properties of the waveguide wall material on the waveguide losses are discussed and theoretical waveguide loss versus wavelength is presented for BeO, Al_2O_3, and fused silica.", "doi": "10.1109/JQE.1973.1077772", "issn": "0018-9197", "publisher": "IEEE", "publication": "IEEE Journal of Quantum Electronics", "publication_date": "1973-09", "series_number": "9", "volume": "9", "issue": "9", "pages": "940-946" }, { "id": "authors:drhp5-m6q62", "collection": "authors", "collection_id": "drhp5-m6q62", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190312-152310160", "type": "article", "title": "Wide-band laser communications in space", "author": [ { "family_name": "Forster", "given_name": "Donald C.", "clpid": "Forster-D-C" }, { "family_name": "Goodwin", "given_name": "Frank E.", "clpid": "Goodwin-F-E" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Candidate wide-bandwidth (1-Gbit/s) satellite laser communications systems are compared on two different bases. First, a comparison is made with projected component technology to establish relative performance between the various approaches based on the fundamental system parameters. From this comparison it appears that the CO_2 (10.6-\u03bcm) system offers a signal-to-noise advantage over the Nd:YAG (1.06-\u03bcm) or doubled Nd:YAG (0.53-\u03bcm) system for a comparable satellite burden. Second, a comparison is made based upon the concept that launch cost for equivalent systems comprises an optimizing criterion. From this comparison it appears that the launch costs for the CO_2 and doubled Nd:YAG systems can be similar, but the latter is very sensitive to the projected weight of a large lightweight \"photon bucket\" receiving aperture. In general, the relative deficiency in signal-to-noise ratio for the Nd:YAG system can only be accommodated through adoption of an open-loop pointing system with an accuracy of 1 \u03bcrad or less, as compared to a closed-loop pointing system with relaxed accuracy for the CO_2 system. The most critical technology problem for the CO_2 system is that of Doppler compensation. These and other critical technologies for both approaches are listed and discussed.", "doi": "10.1109/JQE.1972.1076929", "issn": "0018-9197", "publisher": "IEEE", "publication": "IEEE Journal of Quantum Electronics", "publication_date": "1972-02", "series_number": "2", "volume": "8", "issue": "2", "pages": "263-272" }, { "id": "authors:ret6w-v4574", "collection": "authors", "collection_id": "ret6w-v4574", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIprocieee71", "type": "article", "title": "Ion laser plasmas", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Chester", "given_name": "Arthur N.", "clpid": "Chester-A-N" }, { "family_name": "Halsted", "given_name": "A. Stevens", "clpid": "Halsted-A-S" }, { "family_name": "Parker", "given_name": "Jerald V.", "clpid": "Parker-J-V" } ], "abstract": "The typical noble gas ion laser plasma consists of a high-current-density glow discharge in a noble gas, in the presence of a magnetic field. Typical CW plasma conditions are current densities of 100 to 2000 A/cm^2, tube diameters of 1 to 10 mm, filling pressures of 0.1 to 1.0 torr, and an axial magnetic field of the order of 1000 G. Under these conditions the typical fractional ionization is about 2 percent and the electron temperature between 2 and 4 eV. Pulsed ion lasers typically use higher current densities and lower operating pressures. \n\nThis paper discusses the properties of ion laser plasmas, in terms of both their external discharge parameters and their internal ion and excited state densities. The effect these properties have on laser operation is explained. Many interesting plasma effects, which are important in ion lasers, are given attention. Among these are discharge nonuniformity near tube constrictions, extremely high ion radial drift velocities, wall losses intermediate between ambipolar diffusion and free fall, gas pumping effects, and radiation trapping. The current status of ion laser technology is briefly reviewed.", "doi": "10.1109/PROC.1971.8252", "issn": "0018-9219", "publisher": "IEEE", "publication": "Proceedings of the IEEE", "publication_date": "1971-05", "series_number": "5", "volume": "59", "issue": "5", "pages": "724-739" }, { "id": "authors:0xgrc-shz09", "collection": "authors", "collection_id": "0xgrc-shz09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:GEUprocieee70", "type": "article", "title": "Coherent optical sources for communications", "author": [ { "family_name": "Geusic", "given_name": "Joseph E.", "clpid": "Geusic-J-E" }, { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Pankove", "given_name": "Jacques I.", "clpid": "Pankove-J-I" } ], "abstract": "The development of coherent optical sources, producing usable amounts of power, has provided a stimulus for communications research. Coherent sources in the form of lasers and parametric oscillators are available at wavelengths which span the entire optical spectrum. This paper reviews the state of the art of coherent optical sources with major emphasis on the most highly developed sources.", "doi": "10.1109/PROC.1970.7969", "issn": "0018-9219", "publisher": "IEEE", "publication": "Proceedings of the IEEE", "publication_date": "1970-10", "series_number": "10", "volume": "58", "issue": "10", "pages": "1419-1439" }, { "id": "authors:mbt94-fhj31", "collection": "authors", "collection_id": "mbt94-fhj31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190318-110528697", "type": "article", "title": "High-power CW ultraviolet ion lasers", "author": [ { "family_name": "Bridges", "given_name": "W. B.", "clpid": "Bridges-W-B" }, { "family_name": "Halsted", "given_name": "A. S.", "clpid": "Halsted-A-S" }, { "family_name": "Mercer", "given_name": "G. N.", "clpid": "Mercer-G-N" } ], "abstract": "This paper reports the results of a series of investigations undertaken on CW noble gas ultraviolet ion lasers. We have obtained up to 2.3 W CW UV output power from these tubes, substantially greater than that reported previously. A maximum efficiency of approximately 0.01 percent has been obtained in a practical tube design. A total of 31 violet and ultraviolet laser lines were observed in Ne II, Ar III, Kr III, and Xe III.", "doi": "10.1109/JQE.1969.1081989", "issn": "0018-9197", "publisher": "IEEE", "publication": "IEEE Journal of Quantum Electronics", "publication_date": "1969-06", "series_number": "6", "volume": "5", "issue": "6", "pages": "365" }, { "id": "authors:zfcye-gwj22", "collection": "authors", "collection_id": "zfcye-gwj22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190313-081320548", "type": "article", "title": "Gaussian beam distortion caused by saturable gain or loss", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Results are given for the beam distortion suffered by low order Gaussian-Laguerre modes propagating through a saturable laser amplifier. Both uniform and Bessel small-signal gain distributions are considered. Beam narrowing caused by saturable loss is also treated.", "doi": "10.1109/JQE.1968.1074974", "issn": "0018-9197", "publisher": "IEEE", "publication": "IEEE Journal of Quantum Electronics", "publication_date": "1968-11", "series_number": "11", "volume": "4", "issue": "11", "pages": "820-827" }, { "id": "authors:00j66-69g90", "collection": "authors", "collection_id": "00j66-69g90", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190313-075101063", "type": "article", "title": "Spectroscopy of ion lasers", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" }, { "family_name": "Chester", "given_name": "Arthur N.", "clpid": "Chester-A-N" } ], "abstract": "A brief review of the history of laser oscillation in gaseous ions is given, including a tabulation of wavelengths, classifications, and references for the 230 reported ion laser transitions. Selection rules and excitation mechanisms yielding oscillation are discussed.", "doi": "10.1109/JQE.1965.1072184", "issn": "0018-9197", "publisher": "IEEE", "publication": "IEEE Journal of Quantum Electronics", "publication_date": "1965-05", "series_number": "2", "volume": "1", "issue": "2", "pages": "66-84" }, { "id": "authors:89q0y-dyt45", "collection": "authors", "collection_id": "89q0y-dyt45", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIieeeted65", "type": "article", "title": "Limiting stable currents in bounded electron and ion streams", "author": [ { "family_name": "Bridges", "given_name": "W. B.", "clpid": "Bridges-W-B" }, { "family_name": "Frey", "given_name": "J. I.", "clpid": "Frey-J-I" }, { "family_name": "Birdsall", "given_name": "C. K.", "clpid": "Birdsall-C-K" } ], "abstract": "The classical static analysis of the infinite planar diode has been extended to include the effects of finite transverse beam size. Simple expressions have been found for the increase in maximum stable current density over that of an infinite stream for finite cylindrical and strip streams flowing between plates of infinite diodes. The results are also given in terms of stream perveance. The effect of a nonuniform distribution of current across the stream is shown to be relatively small. Experimental values of maximum stable current agree with those obtained from the analysis. A further extension of the static analysis has been made to include the effects of additional conducting plane boundaries parallel to the stream motion. For length-to-width ratios L/D less than 0.25 the tube is adequately described by the results for the infinite planar diode and for L/D greater than 4, the infinitely-long drift tube theory suffices. At intermediate values of L/D, the maximum amount of current that can be stably passed through the tube is greater than that predicted by either asymptotic theory.", "doi": "10.1109/T-ED.1965.15492", "issn": "0018-9383", "publisher": "IEEE", "publication": "IEEE Transactions on Electron Devices", "publication_date": "1965-05", "series_number": "5", "volume": "12", "issue": "5", "pages": "264-272" }, { "id": "authors:r37br-cn392", "collection": "authors", "collection_id": "r37br-cn392", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIprocieee65", "type": "article", "title": "Mercury-rare gas visible-UV laser", "author": [ { "family_name": "Bridges", "given_name": "W. B.", "clpid": "Bridges-W-B" } ], "abstract": "[No abstract]", "issn": "0018-9219", "publisher": "Proceedings of the IEEE", "publication": "Proceedings of the IEEE", "publication_date": "1965-03-01", "series_number": "3", "volume": "53", "issue": "3", "pages": "309" }, { "id": "authors:p2k6c-g2s70", "collection": "authors", "collection_id": "p2k6c-g2s70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:BRIprocieee64", "type": "article", "title": "Laser action in singly ionized krypton and xenon", "author": [ { "family_name": "Bridges", "given_name": "William B.", "clpid": "Bridges-W-B" } ], "abstract": "Laser oscillation has been observed in pulsed krypton and xenon discharges on 21 wavelengths spanning the visible portion of the spectrum. All lines observed arise from transitions between levels of the singly-ionized state of the atoms (KrII, XeII spectra). The wavelengths and tentative level assignments are given in Table I for krypton and Table II for xenon. Oscillation between energy levels of ions has previously been reported for mercury [1] and argon [2]. The levels reported here are analogous to those observed in argon. The xenon transitions are all s \u2192 p or s' \u2192 p', while the krypton transitions are predominantly of this type, but include one p \u2192 d two p' \u2192 d.", "issn": "0018-9219", "publisher": "Proceedings of the IEEE", "publication": "Proceedings of the IEEE", "publication_date": "1964-07-01", "series_number": "7", "volume": "52", "issue": "7", "pages": "843-844" } ]