A novel distributed feedback laser diode structure for an optical wavelength tunable filter

Abstract

We have studied the effects of introducing phaseshifts in the active section of a 1.5 µm phaseshift-controlled DFB wavelength tunable filter on tuning range, peak power transmissivity and side-mode suppression ratio (SMSR). The analysis indicates that when φ 1 = φ 4 = π/2 the filter wavelength tuning range is 22.1 Å for the grating coupling coefficient κ = 6 mm −1 while maintaining almost constant transmissivity (gain) of more than 35 dB. The filter SMSR ranges from 11.1 to 25.4 dB. The results for asymmetric values of φ 1 and φ 2 are also given.

Facile production of up-converted quantum dot lasers

“…Among such microcavity configurations, the DFB structure has significant appeal because of its single mode emission 16 and its ease of integration into planar laser devices. 17 The DFB architecture comprises a slab waveguide, with a periodic grating, acting as optical gain medium. The laser's output wavelength, l DFB , is defined by the Bragg condition, l DFB ¼ 2h eff L/M, where h eff is the effective refractive index of the gain medium at l DFB , L is the period of the gain modulation structure and M is the Bragg reflection order.…”