The role of optical feedback in a Talbot based cavity has been studied for many years in laser arrays. Yet, those studies mainly deal with improving (or stabilizing) the global, slow-timescale properties of the laser array such as far-field pattern and optical spectrum. In our work, we shed a new light on Talbot based cavity feedback by exploring the fast-timescale properties of each lasers in the array and by studying destabilization instead of stabilization. We experimentally show that a 1D-array of semiconductor lasers emitting around 445 nm exhibits sub-ns intensity fluctuations that can be partially synchronized between lasers.
Complex spatio-temporal dynamics can be observed in single broad-area semiconductor lasers under external optical feedback. Yet, non-linear dynamics is mostly unexplored in large 1D-arrays of lasers. In our recent investigations, we demonstrated both numerically and experimentally that single-mode and broad-area laser arrays in a V-shape external cavity can generate complex spatio-temporal dynamics with typical frequencies in the GHz range as well as periodic and chaotic phase-locking. Feedback misalignment and feedback strength are key parameters to warrant that diode lasers in the array display a variety of dynamics. Potential applications may include directed energy, LIDAR, and random number generators.
High-power, narrow-linewidth blue laser sources with excellent beam quality are important for wide variety of applications including directed energy and underwater communication and sensing. Achieving narrow spectral linewidth from high-power blue semiconductor diode arrays is still a challenge. Our experimental efforts focused on two external cavity schemes involving single broad-area blue diodes and arrays of high-power blue diodes. We demonstrated narrowing the linewidth down to a few dozens of pm. The center wavelength of this narrow optical mode was tunable in the range of several nm and tunability was controlled by the angle of the surface grating providing optical feedback.
Blue diode and diode arrays became recently available commercially and offer a promise for high-power, excellent beam quality, compact and efficient light source for wide variety of applications including phototherapy, sanitization, underwater sensing and communication devices, and directed energy. Due to relatively recent availability on commercial market, these type of diodes and arrays have not yet been extensively studied, for example compared to their near-infrared counterparts. We experimentally investigated two external-cavity schemes involving single broad-area blue lasers and arrays of blue lasers. The feedback provided by a surface grating in Littrow configuration allowed demonstrations of spectral linewidth narrowing, wavelength tuning and paves the way towards locking of multiple diodes in a common external cavity for high-power applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.