Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength
multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of
the MLA has been hampered by a number of issues, particularly wavelength precision and
fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths
of each channel can be determined precisely through low-cost standard μm-level
photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC)
technique. 60-wavelength MLAs with good wavelength spacing uniformity have been
demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation
of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of
employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is
nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%
