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.

Abstract:The re-growth free single mode lasers based on etched slots suitable for photonic integration are presented in this paper. The fabricated 650µm long laser exhibits a threshold current and a slope efficiency of about 32mA and 0.12mW/mA, respectively. The stable single mode operation has been observed with a side mode suppression ratio (SMSR) over 50dB at a current injection of 100mA 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 20nm positive detuning relative to the gain peak. The bandwidth measured is about 3GHz for the integrated device. 326-335 (1996). ©2011 Optical Society of America

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.

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.

Given the tight constraints on the wavelength stability of sources in optical networks, the thermal crosstalk between operating devices in a ten-channel thermally-tunable slotted laser array for DWDM applications has been investigated. It was found experimentally the current standard thermal solution with the laser array chip mounted on an AlN carrier does not allow for wavelength stability of ± 25 GHz ( ± 2 K) with a temperature rise of 5 K measured in a device with 100 mA (CW) applied to a neighbouring laser (device spacing = 360 µm). A combined experimental/numerical approach revealed solid state submounts comprising diamond or highly ordered pyrolytic graphite are inadequate to reduce crosstalk below an allowable level. Numerical simulations of advanced cooling technologies reveal a microfluidic enabled substrate would reduce thermal crosstalk between operational devices on the chip to acceptable levels. Critically our simulations show this reduced crosstalk is not at the expense of device tunability as the thermal resistance of individual lasers remains similar for the base and microfluidic cases.