We use a 37th order grating, an all-active mirror with SOA integrated with laser. Tunable Laser –each laser on array is shifted by 3 nm from neighbour to cover the C-band for wavelength-division multiplexing. Shift obtained simply by varying grating period from one laser to its neighbours.
The two-contact design over front and back sections ensures that all lasers will operate in single mode. We can vary the two currents should multi-mode operation occur to bring about single mode behaviour. The short SOA section is separately contacted.
All lasers in the array operate with threshold current within 19~ 21mA, and a slope efficiency about 0.17 mW/mA. Stable single mode performance with side-mode suppression-ratio (SMSR) >51dB is achieved. Recent designs use three-periods in the grating to improve the operating of the lasers on the blue end of the C-band.
Improved performance of tunable single-mode laser array based on high-order slotted surface grating Abdullaev, Azat; Lu, Qiaoyin; Guo, Weihua; Wallace, Michael J.; Nawrocka, Marta; Bello, Frank; Benson, Aaron; O’Callaghan, James; Donegan, John F. 2015 Optics Express 23(9) 12072-12078