Accession Number : ADP007003

Title :   Coupling Between Barrier and Quantum Well Energy States in a Multiple Quantum Well Optical Amplifier,

Corporate Author : TECHNION - ISRAEL INST OF TECH HAIFA DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Tessler, N. ; Nagar, R. ; Eisentein, G. ; Koren, U. ; Raybon, G.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Multiple quantum well (MQNW) optical amplifiers have recently been demonstrated. It has been shown that these MQW amplifiers have excellent characteristics such as high gain, large saturation power and low noise. In addition to being excellent devices, they can serve as convenient tools to study the gain dynamics in an inverted MQW media. The energy band diagram of a typical 1.5 um InGaAs/InGaAsP MQW optical amplifier. When an electrical pump (DC current) is applied to the device, the allowed states of the structure fill up as the quasi Ferni level rises. Since the amplifier never reaches lasing threshold, there is no pinning of the Ferni level which may rise to a level far in the barrier. In that case, the barrier serves as a carrier reservoir 4. When a strong optical pump is injected at an energy level inside the QW, carriers from higher energies relax to the newly generated empty states. Replenishing of the removed carriers comes first from higher energy levels which are inside the QW (this process has a sub-ps time constant). Then the carriers in the barriers diffuse towards the QW and are captured with a mean time of several ps 4,5. And finally, conventional recombination dominated by Auger processes, with time constants of - 250 ps take place in the barrier region 4.

Descriptors :   *AMPLIFIERS, *OPTICAL EQUIPMENT, ADDITION, AUGERS, BARRIERS, CONSTANTS, DIAGRAMS, DYNAMICS, ENERGY, ENERGY BANDS, ENERGY LEVELS, GAIN, HIGH GAIN, LOW NOISE, MEAN, MEDIA, NOISE, POWER, PUMPS, REGIONS, RESERVOIRS, SATURATION, STRUCTURES, TIME, TOOLS.

Subject Categories : Electrical and Electronic Equipment
      Fiber Optics and Integrated Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE