Tunable ultrafast lasers with adjustable parameters, such as wavelength, intensity, pulse width, and laser states, are desirable as next-generation intelligent light sources. Due to complex nonlinear effects within the ultrafast system, it is challenging for laser state active controlling (LSAC) in ultrafast fiber lasers, especially for passive mode-locking, in a convenient and controllable manner. Anisotropic low-dimensional materials with reduced in-plane symmetry exhibit polarization-dependent properties, providing additional degrees of freedom in compact tunable photonic devices.
In a new paper published in Light Science & Application , a team of scientists led by Professor Pu Zhou from the College of Advanced Interdisciplinary Studies, National University of Defense Technology, China, Professor Kai Zhang from Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, China, and co-workers have achieved the LSAC between conventional soliton (CS) and noise-like pulse (NLP) by polarization control based on a quasi-one-dimensional layered material switcher. The polarization-sensitive nonlinear optical response facilitates the Ta 2 PdS 6 -based mode-lock laser to sustain two laser states, i.e., CS and NLP. The laser state was switchable in the single fiber laser with a mechanism revealed by numerical simulation. Digital coding was further demonstrated in this platform by employing the laser as a codable light source.
Polarization control is a practical approach to adjusting the intracavity parameters and controlling the operating laser states. These scientists summarize the main findings from the tunable ultrafast laser: “(1) the anisotropic quasi-one-dimensional layered material Ta 2 PdS 6 was utilized as a saturable absorber to modulate the nonlinear parameters effectively in an ultrafast system by polarization-dependent absorption; (2) the polarization-sensitive nonlinear optical response facilitates the Ta 2 PdS 6 -based mode-lock laser to sustain two distinct types of laser states, i.e., CS and NLP; (3) the laser state was switchable in the single fiber laser with a mechanism revealed by numerical simulation; and (4) digital coding was further demonstrated in this platform by employing the laser as a codable light source.”
"The controlled and stable switching of distinct pulsed laser modes in a single ultrafast fiber laser system represents significant advances in compact ultrafast photonics, which offers prospects of applications such as communications coding and optical switching.", the scientists forecast.
Light Science & Applications