Sergei A Vasil'ev

Continuous-wave bismuth fibre laser tunable from 1.65 to 1.8 μm

A single-mode fibre based on bismuth-doped germanosilicate glass with a high germanium concentration is considered as an active medium of a laser continuously tunable within the range 1.65 – 1.8 μm. The laser scheme included a broadband ring cavity, and the laser wavelength was controlled by an external plane diffraction grating in the Littrow configuration. For a pump power of 300 mW at a wavelength of 1.564 μm, the maximum output laser power was 15 mW in the zero diffraction order and 6 mW at the fibre output.

Control over the resonance wavelength of fibre Bragg gratings using resistive coatings based on single-wall carbon nanotubes

We demonstrate that a thin resistive coating based on single-wall carbon nanotubes applied to the lateral surface of an optical fibre allows it to be uniformly heated up to a temperature of without damage to the coating. Using a fibre Bragg grating (FBG) as an example, we assess the efficiency of resonance wavelength thermal tuning and examine frequency characteristics that can be achieved using such coating. In particular, we show that the resonance wavelength of the FBG can be tuned over with an efficiency of and time constant of .