AUTHOR=Zhang Aiguo , Qiao Shan , Sheng Liwen , Huang Lin , Liu Zhiming , Ju Junwei , Zhang Zhihui , Yin Bingqi , Li Peng , Liu Jiaqing , Wei Yu 

TITLE=Study on external cavity diode laser with a wide mode-hopping free tuning range

JOURNAL=Frontiers in Physics

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.1093179

DOI=10.3389/fphy.2022.1093179

ISSN=2296-424X

ABSTRACT=<p>A wide mode-hopping free and narrow linewidth tunable laser diode source with a Littman-Metcalf arrangement based on a diffraction grating is presented. Several experiments are carried out to demonstrate the tuning characteristics and spectral linewidth of the proposed external-cavity diode laser source. A wide no mode-hopping continuous wavelength tuning range about 59.13 nm in ultra-C-band with a narrow spectral linewidth of less than 100 kHz is obtained. An optical signal to noise ratio of more than 65 dB and an output power more than 14.8 dBm over the whole tuning range can also be realized in a long-term free running condition. The proposed tunable laser allows simultaneously mode-hopping free and narrow linewidth tunable radiation, thus opening a door for practical application such as coherent detection.</p>