Optical: systems and elements – Optical modulator – Light wave temporal modulation
Patent
1992-09-30
1995-07-25
Lopez, F. Daniel
Optical: systems and elements
Optical modulator
Light wave temporal modulation
257458, 257656, G02F 103
Patent
active
054367565
ABSTRACT:
Photocurrent suppression is achieved without deleteriously affecting modulation performance in a surface normal, electro-absorption, quantum well modulator by introducing a sufficient number of non-radiative recombination centers in the quantum well region of the modulator. The presence of the non-radiative recombination centers significantly shortens the lifetime of photogenerated carriers and, thereby, suppresses the photocurrent. Modulation performance characteristics such as contrast ratio are maintained at acceptable levels even though exciton broadening occurs in the quantum wells. The present modulator exhibits a careful balance between defect density in the quantum wells and the acceptable degree of exciton broadening necessary to preserve quantum effects.
REFERENCES:
patent: 5008717 (1991-04-01), Bar-Joseph et al.
patent: 5105301 (1992-04-01), Campi
patent: 5115335 (1992-05-01), Soref
patent: 5216260 (1993-06-01), Schubert et al.
D. A. B. Miller et al., Physical Review Letters, vol. 53, No. 22, Nov. 26, 1984, "Band-Edge Electroabsorption in Quantum Well Structures: The Quantum-Confined Stark Effect," pp. 2173-2176.
Y. Silberberg et al., Applied Physics Letters, vol. 46, No. 8, Apr. 15, 1985, "Fast Nonlinear Optical Response from Proton-Bombarded Multiple Quantum Well Structure," pp. 701-703.
M. Wegener et al., Applied Physics Letters, vol. 55, No. 6, Aug. 7, 1989, "Electroabsorption and Refraction by Electron Transfer in Asymmetric Modulation-Doped Multiple Well Structures," pp. 583-585.
D. A. B. Miller, Optical and Quantum Electronics, vol. 22, 1990, "Quantum-Well Self-Electro-Optic Effect Devicss," pp. S61-S98.
M. Lambsdorff et al., Applied Physics Letters, vol. 58, No. 17, Apr. 29, 1991, "Subpicosecond Carrier Lifetimes in Radiation-Damaged GaAs," pp. 1881-1883.
W. H. Knox et al., Applied Physics Letters, vol. 59, No. 12, Sep. 16, 1991, "Low-Temperature-Grown GaAs Quantum Wells: Femtosecond Nonlinear Optical and Parallel-Field Transport Studies," pp. 1491-1493.
T. K. Woodward et al., Applied Physics Letters, vol. 60, No. 6, Feb. 10, 1992, "Suppressed Photocurrent Multiple-Quantum-Well Optical Modulators by Proton Implantation," pp. 742-744.
Knox Wayne H.
Stark Jason B.
Tell Benjamin
Woodward Ted K.
AT&T Bell Laboratories
Lopez F. Daniel
Ranieri Gregory C.
LandOfFree
Suppressed photocurrent, quantum well optical modulation device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Suppressed photocurrent, quantum well optical modulation device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suppressed photocurrent, quantum well optical modulation device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-743862