Narrow linewidth 1560  nm InGaAsP split-contact corrugated ridge waveguide DFB lasers

Abstract

We demonstrate a split-contact corrugated ridge waveguide InGaAsP distributed feedback laser at 1560 nm. The laser cavity has been defined with uniform third-order gratings etched along the sidewalls of the ridge waveguide. The gratings were fabricated using a standard I-line stepper lithography technique along with an inductively coupled reactive ion-etching process. Stable single-mode operation has been achieved with side-mode suppression ratios ≥50 dB, output powers ≥7 mW, a wavelength tuning range ≥2.3 nm, and narrow linewidths (≤140 kHz) for different biasing conditions, with a minimum of 70 kHz. The effect of p-contact partition on device performance is also studied.

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].…”

“…As β increases, formula (13) approaches that giving the inverse lifetime of a quantum well such that: …”

Laterally coupled distributed feedback lasers emitting at 2 μm with quantum dash active region and high-duty-cycle etched semiconductor gratings

“…[22][23][24][25] In additional recent work, improvements in low-loss, high-power operation have been achieved by etched lateral grating fabrication, 13 or by use of a twostep ridge etch process for minimal lateral current spreading. 26 On the other hand, higher side mode discrimination in relatively short cavities has been achieved by operation with a narrower ridge waveguide of 1.7 lm width, 27 introducing first-order 28,29 or optimized third-order [30][31][32][33][34] Bragg gratings on the ridge waveguide sidewalls, or by use of focused ion beam lithography (FIB) in LC-DFB 35 and LC-DBR 36,37 configurations. Notably, chirped CRW gratings for the better control over the coupling coefficient have been also investigated.…”