ИСТИНА

Highly stable narrow-linewidth single frequency lasers are widely used both in scientific research and in multiple applications such as fiber-optic communications, distributed fiber optic sensing (including coherent reflectometry [1-3]), radio over fiber technology, optical interferometry etc. In addition to the low level of phase and amplitude noises of laser radiation, most of these applications also require compactness, portability, easy and low cost production combined with various methods of phase noise reduction: laser diode coupled with an external whispering gallery modes (WGM) optical cavity [4, 5] (e.g. OE Waves lasers), a laser diode with external planar Bragg grating (BR) [6] (e.g. RIO “Orion” laser) and a single-frequency DFB fiber laser (e.g. EFL-SF-1550 laser manufactured by Inversion Fiber, LLC).