J. E. Geusic
Bell Labs
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Featured researches published by J. E. Geusic.
Journal of Applied Physics | 1966
F. S. Chen; J. E. Geusic; S. K. Kurtz; J. G. Skinner; S. H. Wemple
The dielectric and electro‐optic properties of KTaxNb1−xO3(KTN) are discussed from the point of view of the materials usefulness in light modulators and beam deflectors. It is shown that baseband light modulators with 200‐ to 300‐Mc/sec bandwidths and analog deflectors with 200 to 300 resolvable spots are within the practical capabilities of this material.
Applied Physics Letters | 1967
L. G. Van Uitert; S. Singh; H. J. Levinstein; J. E. Geusic; W. A. Bonner
The nonlinear coefficient d31 of K.6Li.4NbO3 is equal to d31 of LiNbO3. Also, the serious problem of optically induced refractive‐index inhomogeneities which has been observed in many nonlinear materials, notably LiNbO3, is not observed in this new material. The electro‐optic half‐wave voltage of this new material is 930 V.
Applied Physics Letters | 1968
R. G. Smith; J. E. Geusic; H. J. Levinstein; J. J. Rubin; S. Singh; L. G. Van Uitert
A tunable, optical parametric oscillator using a continuous pump is reported. The threshold was measured to be 45 mW of multimode power at .532 μ. The efficiency was found to be 1% with 300 mW of pump power.
Applied Physics Letters | 1968
J. E. Geusic; H. J. Levinstein; S. Singh; R. G. Smith; L. G. Van Uitert
A continuous 0.532‐μ solid‐state source utilizing the nonlinear material Ba2NaNb5O15 inside the cavity of a 1.064‐μ YAlG:Nd laser has generated 1.1 W of coherent green power. This represents 100% conversion to the green of the available infrared radiation from the YAlG:Nd laser utilized.
Proceedings of the IEEE | 1970
R. Chesler; M.A. Karr; J. E. Geusic
An acoustooptic loss modulator made by bonding an X-cut quartz transducer to a fused silica scattering medium offers a practical means for repetitively Q-switching continuously pumped Nd : YAlG lasers at repetition rates up to 50 kHz. The peak power output of a multitransverse mode laser is typically enhanced by a factor of about 500 relative to CW operation at low (≪5 kHz) repetition rates and by larger factors when the transverse mode structure is suitably restricted. At high repetition rates, the peak power becomes smaller and the average power output approaches the CW level. The theoretical Q-switching behavior derived from the rate equations governing an ideal four-level laser is presented in graphical form, and is found to describe the observed behavior well when the laser is restricted to oscillation in the TEM 00 transverse mode. Similar calculations for Q-switched intracavity second harmonic generation indicate that the peak output power available at the second harmonic slightly exceeds that available at the fundamental, and that the harmonic coupling necessary to optimally couple the Q-switched laser is several orders of magnitude smaller than that required for CW intracavity conversion. Experiments using Ba 2 NaNb 5 O 15 For intracavity Q-switched harmonic generation roughly verified these predictions. A peak power output of 220 watts at 0.532 µ in the TEM 00 mode was achieved. Surface pitting of the nonlinear crystal after a few hours of operation prevented a thorough comparison with the calculated results. Preliminary experiments using the doubled Q-switched Nd : YAlG laser and an ammonia dihydrogen phosphate crystal to generate ultraviolet (the 0.266-µ harmonic) yielded a peak output power of 40 watts.
Applied Physics Letters | 1969
L. F. Johnson; J. E. Geusic; H. J. Guggenheim; T. Kushida; S. Singh; L. G. Van Uitert
The mechanisms relating to infrared‐pumped visible and ultraviolet emission observed from Yb3+–Er3+ and Yb3+–Ho3+ ions in BaYF5 and Y3OCl7 (reported in the companion papers) are discussed. An analysis is given of the material parameters required for efficient conversion and the limiting performance which can be expected from a near ideal material is indicated.
Applied Physics Letters | 1969
L. G. Van Uitert; S. Singh; H. J. Levinstein; L. F. Johnson; W. H. Grodkiewicz; J. E. Geusic
When pumped by radiation from a Si–GaAs diode, the luminous efficiency of Y3OCl7:Yb3+, Er3+ is comparable to that of visible emitting GaP diodes. By varying the Yb3+ concentration, phosphors have been made which produce a red or yellow visual response.
Journal of Applied Physics | 1971
J. E. Geusic; F. W. Ostermayer; H. M. Marcos; L. G. Van Uitert; J. P. van der Ziel
Efficiencies of ∼1%, 0.1%, and 0.01% have been achieved, respectively, in the red, green, and blue with simple infrared‐to‐visible conversion sources. Saturation effects observed in the blue‐emitting phosphor Y0.65Yb0.35Tm0.001F3 have been explained. The first and second cross‐transfer coefficients for this Yb, Tm system have been determined to be 1.3×10−17 and 8.3×10−15 cm3 sec−1.
IEEE Transactions on Magnetics | 1973
P. Bonyhard; J. E. Geusic; Andrew Henry Bobeck; Yu-Ssu Chen; Paul C. Michaelis; J. L. Smith
The choice and organization of bubble-circuit functions in the design of a magnetic bubble mass memory chip are discussed with emphasis on factors such as circuit function compatibility and performance, circuit density, and processing simplicity. A specific major-minor organized chip design is described which uses rotating field driven propagation,
Materials Research Bulletin | 1973
W. A. Bonner; J. E. Geusic; D.H. Smith; L. G. Van Uitert; G. P. Vella‐Coleiro
-sign transfer gates, all T-bar minor loops, a nucleate generator with chevron merging port, a chevron based replicator/ annihilator and a chevron guard rail expander detector. The overall operating characteristics of chips having 20 510 bits of storage capacity have been measured and a bias field margin of 12 Oe is typically obtained with a 25 Oe, 100 kHz rotating field.
