Wavelength tunable sampled grating distributed Bragg reflector (SG-DBR) lasers used for telecommunications applications have previously demonstrated the ability for linear frequency ramps covering the entire tuning range of the laser at 100 kHz repetition rates. An individual SG-DBR laser has a typical tuning range of 50 nm. The InGaAs/InP material system often used with SG-DBR lasers allows fo...

Nano fabricated amplifier for semiconductor epitaxial laser A major challenge for building a widely tunable external cavity Mid-Infrared (MIR) laser using latest semiconductor epitaxial (epi) laser is to apply the Anti-Reflection (AR) coating that could turn the otherwise Fabry-Perot (FP) epi laser waveguide into an amplifier. As the epi laser waveguide are progressing rapidly in terms of tunin...

A novel coupled-cavity Ti:sapphire oscillator architecture featuring a volume Bragg grating as a feedback element is presented. The oscillator provides continuous wave lasing within a spectral linewidth as narrow as 5 pm. The output can be wavelength-tuned over an ultrabroad spectral range of 130 nm, extending from 714 to 842 nm. This unique combination of narrow spectral linewidth and wide tun...

We report simple and compact V-cavity semiconductor laser capable of full-band wavelength tuning. A half-wave coupler is used to obtain high side-mode suppression ratio (SMSR) without any grating or epitaxial regrowth. Temperature induced gain spectrum shift is employed in combination with the Vernier tuning mechanism to extend the wavelength tuning range beyond the free spectral range limit. W...

Large spectral tuning of a water-glycerol microdroplet standing on a superhydrophobic surface by local heating with a focused infrared laser is studied both experimentally by optical spectroscopy and computationally using a lumped system formulation of the mass and heat transfer between the microdroplet and the chamber. The effects of optical scattering force, chamber humidity, size of microdro...

We report advances in compression tuning of fused-silica microsphere whispering-gallery resonances and a practical use of the improved compression tuner. The advances include extending the tuning range and enhancing the tuner’s response speed; these lead to the new application of using the tuner to lock to a laser, keeping a single whispering-gallery mode on resonance as the laser frequency is ...

We report the development of ring-cavity tunable fiber laser based on tunable fiber Bragg gratings integrated optical circulator. The tunable laser, operates in the C band, has laser linewidth, power variation and tuning range of 0.015 nm, ±0.5 dB and 31.0 nm, respectively. As 40 mW of pump power is used, the ring-cavity tunable laser has a side mode suppression ratio of 60 dB and power convers...

A scheme for generating multiwavelength laser source based on a linear optical amplifier (LOA) is demonstrated for potential applications in dense-wavelength division multiplexing (DWDM) communication systems. The laser output shows up to 80 laser lines (SNR at least 20 dB) with 0.4 nm channel spacing covering C and L band. Simultaneous tuning of muti-wavelengths is also demonstrated.

A wavelength-tunable single-frequency fiber laser based on the spectral narrowing effect in a nonlinear semiconductor optical amplifier (NL-SOA) is proposed and experimentally demonstrated. The single-frequency operation is achieved based on the spectral narrowing effect resulted from the inverse four-wave mixing in a NL-SOA. By incorporating the NL-SOA in the fiber laser cavity, single-frequen...

In order to obtain an accurate Avogadro constant with a relative uncertainty of 1×10 to redefine the kilogram, the diameter of a perfect single crystal silicon sphere is required with the measurement uncertainty of 0.3 nm using the X-ray crystal density method. To achieve this, phase-shifting interferometers have been developed. A laser frequency tuning system calibrated by a Fabry-Perot cavity...