InGaAs/InGaAsP diffused quantum wells optical amplifiers and modulators

Abstract

Diffused quantum wells (DFQW) optical devices have been widely investigated for use in optical electronics integrated circuits. In this paper, we report on the performance of five-period (200Å In0.53Ga0.47As0.57P0.43 barrier and 60Å In0.53Ga0.47As well) DFQW optical amplifiers and modulators. The results show that the QW amplifiers and modulators maintain at single guiding mode operation after the QW structure has been annealed. The tuning range of the operational wavelength of QW optical amplifiers is 34meV without a significant degradation in the modal gain peak by interdiffusing the QWs. The QW interdiffusion was accomplished by P+ ion implantation to the upper region of the top cladding layer of the multilayer structure and followed by rapid thermal annealing such that the implanted ions did not damage the QW structures. The I-V characteristics of the implanted QW are similar to that of the unimplanted. Concerning the TE electro-absorptive modulation, a large contrast ratio (CR) of 35dB can be obtained at λopn = 1.55μm under a small bias of -1.5V for a 500μm long modulator. For TM mode, a slightly higher CR of 37dB can be obtained at the operation wavelength although the reverse bias voltage is double.