Lasing features of the ultra-short Fabry–Perot cavity on the basis of a photosensitive Er/Yb-doped multimaterial fiber with a silicophosphate core

The lasing properties of a short-cavity laser based on the Er/Yb composite fiber with a silicophosphate core in a silica cladding were investigated in detail. A Fabry–Perot cavity was manufactured on a 25 mm long fiber segment using the ultraviolet (UV) ( λ =193nm) excimer laser radiation and phase-mask technique of Bragg grating inscription. The laser with an effective cavity length of 11 mm generated single-frequency radiation centered at 1554.45 nm. This laser demonstrated strictly continuous-wave operation under 974 nm pumping but self- Q -switched operation under 1485 nm pumping. Under 974 nm pumping, the slope efficiency was as high as 4%, and the output power reached 17 mW—a level comparable with the characteristics of commercial single-frequency laser diodes.