Chirped DFB Grating for Narrow Linewidth Lasers

No abstract available

1.4 million Q factor Si₃N₄ micro-ring resonator at 780 nm wavelength for chip-scale atomic systems

A silicon nitride micro-ring resonator with a loaded Q factor of 1.4 × 10⁶ at 780 nm wavelength is demonstrated on silicon substrates. This is due to the low propagation loss waveguides achieved by optimization of waveguide sidewall interactions and top cladding refractive index. Potential applications include laser frequency stabilization allowing for chip-scale atomic systems targeting the ⁸⁷Rb atomic transition at 780.24 nm. The temperature dependent wavelength shift of the micro-ring was determined to be 13.1 pm/K indicating that a minimum temperature stability of less than ±15 mK is required for such devices for wavelength locking applications. If a polyurethane acrylate top cladding of an optimized thickness is used then the micro-ring could effectively be athermal, resulting in reduced footprint, power consumption, and cost of potential devices

Narrow Linewidth Distributed Feedback Diode Lasers for Cooling in Cold Atom Systems

Distributed feedback (DFB) lasers have been realized emitting at a wavelength of 780.24 nm which demonstrate powers in excess of 60 mW with 612 kHz linewidth for use in rubidium (87Rb) cold atom systems

1.4 Million Q-Factor 780 nm Wavelength Si3N4 Micro-rings for Chip-Scale Atomic Systems

A silicon nitride micro-ring resonator with loaded Q factor of 1.4 million at 780 nm wavelength on silicon substrates for chip-scale atomic systems targeting the 87Rb atomic transition at 780.24 nm

Distributed Feedback Lasers for Quantum Cooling Applications

There is an ever-growing need for compact sources which can be used for the cooling process in high accuracy atomic clocks. Current systems make use of large, expensive lasers which are power-hungry and often require frequency doubling in order to hit the required wavelengths. Distributed feedback (DFB) lasers have been fabricated at a number of key wavelengths which would allow chip scale atomic devices with very high accuracy to become a reality. Two key atomic transitions analysed here are 88 Sr + and 87 Rb which require cooling at 422 nm and 780.24 nm, respectively. The vital parameter of the DFB lasers for this application is the linewidth, as very narrow linewidths are required in order for the atomic cooling process to occur. The lasers realised here produce the required power levels, with high side-mode suppression ratios and show good single mode tuning which is important for hitting precise wavelengths. This work will present the latest techniques and results using the DFB lasers at both wavelengths

Fabrication of quasi phase matched GaAs crystals using a novel glass bonding technique

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Chirped DFB Grating for Narrow Linewidth Lasers

No abstract available

Sub-MHz linewidth distributed feedback laser at 780.24-nm emission wavelength for 87Rb applications

A GaAs/AlGaAs distributed feedback semiconductor (DFB) laser with a laterally-coupled grating is demonstrated at a wavelength of 780.24 nm with an output power up to 60 mW. A mode expander and aluminum-free active layers have been used in the material epilayer to reduce the linewidth to 612 kHz while maintaining high output power. The fabricated laser demonstrates over 40 dB side-mode suppression ratio with tuning range > 0.3 nm, which is suitable for atom cooling experiments with the D2 87Rb atomic transition and provides substantial potential for the laser to be integrated into miniaturized cold atom systems

Multi-output Q-switched solid-state laser using an intra-cavity MEMS micromirror array

Multiple individually-controllable Q-switched laser outputs from a single diode-pumped Nd:YAG module are presented by using an electrostatic MEMS scanning micromirror array as cavity end-mirror. The gold coated, 700 μm diameter and 25 μm thick, single-crystal silicon micromirrors possess resonant tilt frequencies of ~8 kHz with optical scan angles of up to 78°. Dual laser output resulting from the actuation of two neighboring mirrors was observed resulting in a combined average output power of 125 mW and pulse durations of 30 ns with resulting pulse energies of 7.9 μJ and 7.1 μJ. The output power was limited by thermal effects on the gold-coated mirror surface. Dielectric coatings with increased reflectivity and therefore lower thermal stresses are required to power-scale this technique. An initial SiO2/Nb2O5 test coating was applied to a multi-mirror array with individual optical scan angles of 14° at a resonant tilt frequency of 10.4 kHz. The use of this dielectric coated array inside a 3-mirror Nd:YAG laser cavity led to a single mirror output with average Q-switched output power of 750 mW and pulse durations of 295 ns resulting in pulse energies of 36 μJ