The first experimental realization of a 20-wavelength distributed feedback semiconductor laser array with a λ/4 equivalent phase shift using common holographic exposure in the 1.3-μm wavelength domain is reported. It shows very good linearity in lasing wavelengths with a deviation from −0.5 to 0.45 nm. The threshold currents are between 13 and 17 mA. The side mode suppression ratios are all larger than 40 dB under the bias currents of 70 mA. The slope efficiencies at room temperature are all about 0.4 W/A. However, it only changes the micrometer-level sampling structures while the seed grating is uniform. Therefore, its fabrication cost is low.
A dual-wavelength laser array is obtained by two asymmetric phase shifts. Different wavelength spacings are obtained by varying the magnitude of the phase shifts. The phase shifts are distributed along two phase-arranging regions, which are obtained equivalently by specially-designed sampled structures with uniform seed gratings.
A laser array, which is consisted of 56 π equivalent phase shift (EPS) sampled Bragg grating (SBG) semiconductor laser, is experimentally investigated. The experimental results show the influence of the sampling duty cycle fabrication error on the lasing wavelength of an SBG semiconductor laser can be ignored.
A distributed feedback (DFB) semiconductor laser with multiple phase shifts based on reconstruction equivalent chirp
(REC) technology is numerical studied and fabricated. The simulation results show that the performances of the multiple
phase shifts DFB semiconductor laser based on REC technology are nearly the same as the actual multiple phase shifts
DFB laser. They have the same P-I curves, the internal power distributions and the output ASE spectra. However, it only
changes the sampling structures of the REC based laser with the uniform seeding waveguide grating. So the fabrication
of such laser is very easy. In this paper, the fabrication of this structure was realized for the first time to the best of our
knowledge. The experimental results show that it has good single longitudinal mode operation even under high injection
current with side mode suppression ratio (SMSR) above 55dB even at high injection current.