Improved performance of tunable single-mode laser array based on high-order slotted surface grating.

We present an improved design of a wavelength-tunable single-mode laser array based on a high order surface grating with non-uniformly spaced slots. The laser array consists of 12 slotted single-mode lasers. The fabricated device exhibits a quasi-continuous tuning range of more than 36 nm over the temperature range from 10°C - 45°C covering the full C-band. All lasers in the array have stable single-mode operation with side mode suppression ratio of 50 dB due to the modified slot design. A spectral linewidth of less than 500 kHz was obtained for all channels in the array.

Widely tunable six-section semiconductor laser based on etched slots.

A six section widely tunable laser based on slots etched into the waveguide is presented. This laser is re-growth free which makes it suitable for photonics integration. To improve the laser performance, the front and the back facets are anti- reflection (AR) coated and the laser is integrated with a semiconductor optical amplifier. A tuning range of 55nm covering 12 supermodes with side mode suppression ratio (SMSR) >30dB is reported for the fabricated device using the Vernier tuning effect. This laser platform requires very simple fabrication compared with more complex superstructure gratings.

Nine-channel wavelength tunable single mode laser array based on slots.

A 9-channel wavelength tunable single-mode laser array based on slots is presented. The fabricated laser array demonstrated a threshold current in a range of 19~21 mA with the SOA unbiased at 20°C under continuous wave condition. Stable single mode performances have been observed with side-mode suppression-ratio (SMSR) > 50 dB. The output power higher than 37 mW was obtained at the SOA injected current of 70 mA for all the 9 channels within the laser array. A wavelength quasi-continuous tuning range of about 27 nm has been achieved for the laser array with the temperature variations from 10°C to 45°C. This array platform is of a single growth and monolithically integrable. It can be easily fabricated by standard photolithography. In addition, it potentially removes the yield problem due to the uncertainty of the facet cleaving.

Single mode lasers based on slots suitable for photonic integration.

The re-growth free single mode lasers based on etched slots suitable for photonic integration are presented in this paper. The fabricated 650 µm long laser exhibits a threshold current and a slope efficiency of about 32 mA and 0.12 mW/mA, respectively. The stable single mode operation has been observed with a side mode suppression ratio (SMSR) over 50 dB at a current injection of 100 mA for the fabricated laser. Such a laser integrated with electroabsorption (EA) modulator is also demonstrated. The integrated device has an extinction ratio over 10 dB at 2.2V driving voltage with the lasing wavelength of around 20 nm positive detuning relative to the gain peak. The bandwidth measured is about 3 GHz for the integrated device.