Simulation of an AlGaInAs/InP Electro-Absorption Modulator Monolithically Integrated with Sidewall Grating Distributed Feedback Laser by Quantum Well Intermixing

Abstract

A novel AlGaInAs/InP electro-absorption modulated laser (EML) with a simple fabrication process is proposed, in which the electro-absorption modulator (EAM) has a 10 nm blueshift induced by quantum well intermixing (QWI) and is monolithically integrated with a sidewall grating distributed-feedback (DFB) laser working at 1.55 μm wavelength. The extent of the QWI process is characterized by a diffusion length. The quantum confined Stark effect (QCSE) is simulated in terms of extinction ratio (ER) and chirp for bias electric fields from 0 kV/cm to 200 kV/cm and for different amounts of intermixing. The results indicate that for a 150 µm-long EAM with a 10 nm blueshift induced by QWI, an ER of 40 dB is obtained at 2.5 V reverse bias with no penalty in chirp compared to an as-grown quantum well (QW) and the insertion loss at 0 V bias is 0.11 dB for 1.55 µm operation wavelength. The simulated –3 dB bandwidth of the electrical to optical power response is 22 GHz.

Regrowth-free AlGaInAs MQW polarization controller integrated with a sidewall grating DFB laser

“…In Ref. [13], we have proposed a PMC device with a 100 nm blueshift by QWI; the degree of intermixing N (z, L D ) is represented by the diffusion length (L D ) on the group III substance as…”

“…As reported in Ref. [13], the TE and TM absorption coefficients in the DPS with a 100 nm blueshift by QWI can also be calculated using Eqs. ( 5)-( 7) and are presented in Fig.…”

“…The two main mechanisms of SOP conversion are the mode-evolution method [12], which utilizes the shifting of the propagating mode inside the waveguide, and the mode coupling method [8], which exploits the beating between two eigenmodes to enable polarization rotation along the PMC waveguide. Because mode coupling PMCs enable polarization conversion within a short length of waveguide, it is important to reduce the absorption loss caused by the inter-band exciton transitions inside an MQW-based PMC monolithically integrated with an MQW-based LD [13]. To realize good mode-matching between the waveguides of monolithic PMCs and LDs, we have proposed an AlGaInAs/InP MQW-based sidewall grating (SWG) DFB laser monolithically integrated with a stepped height waveguide PMC [14].…”