Narrow Linewidth 1550 nm Corrugated Ridge Waveguide DFB Lasers

Abstract

We report on the design and characterization of InP-based multiple quantum well corrugated ridge waveguide distributed feedback diode lasers operating at 1550 nm. Thirdorder gratings have been etched along the sidewalls of the ridge waveguide using the standard I-line stepper lithography technique with an inductively coupled reactive ion etching process. An as-cleaved 1500-μm-long laser diode shows stable continuous wave single-mode operation at 1550 nm with high side-mode suppression ratios (>50 dB), a temperature-dependent wavelength shift dλ/dT ∼0.095 nm/°C, and output powers ≥7 mW at 25°C. Linewidth determination has been carried using the delayed self-heterodyne interferometric technique. Narrow linewidths (≤250 kHz) have been observed for a wide range of current injection, with a minimum of 184 kHz at 300 mA.Index Terms-Distributed feedback (DFB) lasers, delayed selfheterodyne interferometry, InP/InGaAsP multiple quantum well (MQW), Lorentzian lineshape, stepper lithography, Voigt profile.

Optically integrated InP-Si3N4 hybrid laser

“…4 suggests that a factor of ten increase in the output power might be achieved at high driving currents. Considering that the linewidth reduces inversely proportionally with increasing output power [41], [42], a linewidth reduction by a factor of ten might be possible, yielding linewidths at the ten-kHz level.…”

The Linewidth Broadening Factor: A Length-Scale-Dependent Analytical Approach

“…The linewidth two-order-enhancement (18) is a gauge of further spectral purity of which, the potential can be reaped by tailoring the exciton within an advanced cavity such as lateralcoupling distributed feedback (LC-DFB) lasers [13,14,15].…”

Surface Grating Fabrication by Inductively Coupled Plasma Dry Etching for InP-Based Photonic Integrated Circuits

“…Indium phosphide (InP) based semiconductor materials are particularly attractive for optoelectronics, as they allow monolithic integration of a variety of photonic devices including semiconductor lasers, modulators, semiconductor optical amplifiers, photodetectors, polarization convertors, and etc . Surface gratings are widely used in photonic integrated circuits (PICs) . Compared with buried gratings normally employed in semiconductor distributed feedback (DFB) lasers, surface gratings are advantageous in dispensing with the critical regrowth process, thus greatly simplifying the fabrication and improving the yield.…”

“…[1][2][3] Surface gratings are widely used in photonic integrated circuits (PICs). [4][5][6] Compared with buried gratings normally employed in semiconductor distributed feedback (DFB) lasers, surface gratings are advantageous in dispensing with the critical regrowth process, thus greatly simplifying the fabrication and improving the yield.…”