Active stabilization of the DFB laser injection-locked to an external fiber-optic ring resonator

Autor: Igor O. Zolotovskii, Patrice Mégret, Vasily V. Spirin, Andrei A. Fotiadi, Dmitry A. Korobko, Krassimir Panajotov, J. L. Bueno Escobedo
Přispěvatelé: Sciamanna, Marc, Michalzik, Rainer, Panajotov, Krassimir, Hofling, Sven, Brussels Photonics Team, Applied Physics and Photonics
Jazyk: angličtina
Rok vydání: 2020
Předmět:
DOI: 10.1117/12.2557672
Popis: Spectrally pure lasers are the heart of precision high-end scientific and commercial applications. Self-injection locking of a DFB laser through an external feedback is one of the most promising mechanisms for the laser line narrowing. To provide the effect, a part of the optical radiation emitted by the laser is returned back into the laser cavity. This relatively simple technique allows to design cost-effective narrow-band laser sources based on standard laser diodes making them an attractive solution in comparison with conventional laser systems based on an active feedback. Recently, we have demonstrated significant line narrowing (similar to 1000 times) of a conventional low-cost DFB laser locked to an external fiber optic ring resonator. Once locking, any slow change of resonator mode frequency (due to temperature fluctuations, for example) leads to a simultaneous change of the laser generation frequency. However, in real conditions, in the presence of environment noise the stable laser operation in a single longitudinal mode occurs within a time interval limited to several seconds. These intervals are interrupted by short-time jumps in the lasing intensity caused by laser mode-hopping. Here, we report on linewidth narrowing and stabilization of semiconductor DFB laser implementing the self-injection locking in conjugation with an active optoelectronic feedback controlled by the simplest low-cost USB-DAQ card. In this assemble, the principle laser linewidth narrowing is provided by the self-injection-locking mechanism, whereas the applied active feedback helps to maintain this passive stabilization regime. Therefore, in terms of the feedback bandwidth, complexity, and allocated memory the proposed combined solution is much less consuming than active stabilization schemes based on the Pound-Drever-Hall (PDH) and Hansch-Couillaud methods commonly used with fiber lasers. Moreover, we will show that the active optoelectronic feedback which is initially implemented for better laser stabilization plays a second role granting control and tunability to laser linewidth.
Databáze: OpenAIRE