Static and Dynamic Characteristics of Digital Wavelength Switching in V-Coupled-Cavity Semiconductor Laser

The static and dynamic characteristics of digital wavelength switching in a novel V-coupled-cavity semiconductor laser is investigated. In contrast to previously investigated Y-laser, the V-shaped coupler can realize not only an optimum coupling coefficient but also a ??-phase difference between the cross-coupling and self-coupling coefficients, which results in a high single-mode selectivity. It is shown that while switching to an optimal current value results in the maximal output power and maximal side-mode suppression ratio (SMSR), the digitally wavelength switchable laser has a good tolerance on the accuracy of the switching current. For a current deviation corresponding to ??25% of the channel spacing, the SMSR only degrades by about 5.2 dB, while the wavelength varies by only ??0.01 nm from the set value for the case of 0.8 nm channel spacing. The dynamic properties including the switching transients and switching delay are also investigated and discussed.