High-Power Linearly-Polarized Supercontinuum Fiber Source Based On Polarization Maintaining Photonic Crystal Fiber

Linearly-polarized supercontinuum(SC)fiber laser sources have important applications in fields like biomedical detection and target detection and identification.At present,the linearly-polarized SC is implemented mainly by adopting spatial coupling to pump laser pulses into high birefringent photonic crystal fibers,the output power is low,the spectrum is hard to cover the entire wavelength range of the visible and near-infrared band,and the traditional extinction ratio measurement can't represent each wavelength within the wide spectrum at a high power level.Therefore,this paper carried out theoretical and experimental research on the generation and measurement of high-power linearly-polarized SC.The main content includes the following aspects:1.An all-fiber linearly-polarized supercontinuum laser source was designed.A hundred-watt level linearly-polarized SC laser source with spectrum ranges from 520 to2300 nm is successfully achieved.It is the first linearly-polarized SC configuration based on polarization-maintaining photonic crystal fiber in an all fiber structure.The slope efficiency is 68.2% and the 10-d B spectrum range is 600-1800 nm.This linearlypolarized SC fiber laser source is the highest power with such a wide spectrum until now,which is three orders of magnitude higher than the publicly reported level.2.We put forward a novel method for measuring each wavelength's polarization extinction ratio(PER)within a wide spectrum at a high-power level.The measuring system consists of polarization-maintaining fibers with 45° spliced angle and a PBS which axis is 45 ° respect to the polarization-maintaining fiber.Using the method for high-power linearly-polarized SC spectrum testing,the PER is greater than 15 d B,which is the same as that measured by commercial extinction ratio meter under low power condition.