Passively q-switched raman fiber laser source widely tunable in near infrared and visible window

Citation

[1]

A. Goswami, S. Dash, V. R. Supradeepa, S. Padmanabhan, and J. Prakash, “Passively Q-switched Raman fiber laser source widely tunable in near infrared and visible window,” in Nonlinear frequency generation and conversion: Materials and devices XXIV, SPIE, 2025, p. 133470T. doi: 10.1117/12.3043020.

Abstract

In the current study, we demonstrate a pulsed cascaded Raman fiber laser (CRFL) widely tunable in both the second near infrared (NIR-II) (1060-1600nm) and visible window (530-600nm, limited currently only by crystal availability in house). We achieved wide wavelength tunability of the CRFL by using an in-house built passively Q-switched tunable Yb-doped fiber laser as pump. The Yb-pump is followed by a large-mode area fiber amplifier for pulse-energy scaling and a Raman module for efficient Raman conversion. Subsequently, the NIR CRFL is used as a pump for generating visible light in a second-harmonic generation module, implementing a type-I cut LBO crystal. The CRFL operates at tunable high repetition rate variable from 20kHz to 80kHz. Pulse-duration can also be changed in the range from 40ns to 200ns, by minor modifications. Source is packaged for implementation in a wide range of biomedical imaging applications.