Ultra-compact all-fiber narrow-linewidth single-frequency blue laser at 489 nm

Abstract

Due to large coherence length, high detection sensitivity and feasible design, a narrow-linewidth single-frequency laser in the blue spectral range is essential for underwater communication and high-resolution atomic/molecular spectroscopy. By exploiting the efficient frequency doubling of a 978 nm Yb-doped phosphate fiber laser in a fiber-coupled 10 mm long periodically poled LiNbO3, an all-fiber single-frequency blue laser at 489 nm with an ultra-compact and practical design is demonstrated. Over 68 mW of stable narrow-linewidth blue radiation is generated with a conversion efficiency of 30.3%. The estimated laser linewidth is less than 15 kHz, while the measured relative intensity noise is less than –139 dB Hz−1 at frequencies above 20 MHz. The obtained blue laser output is naturally stable with a power stability of ±1.5% over a period of 120 min.

Optimization of Nd-Doped LMA Fibers for High-Power Laser Emission Near 915 nm

“…Such laser sources can be used for core-pumping of Ytterbium-doped short fiber oscillators and amplifiers [1], [2], [3] or for specific applications in biomedicine such as twophoton microscopy [4]. These laser sources can also give access to pure blue or blue/green wavelengths between 450 nm and 500 nm after second harmonic generation (SHG) [5], [6], replacing bulky and inefficient Argon ion laser. The 3levels laser transition 2 F5/2 2 F7/2 of the Yb 3+ ion has already This work was supported in part by the Agence Nationale de la Recherche (NEODUV ANR-19-CE24-0029) and the Région Normandie (PICODUV Project).…”

650 W All-Fiber Single-Frequency Polarization-Maintaining Fiber Amplifier Based on Hybrid Wavelength Pumping and Tapered Yb-Doped Fibers

“…Research and development into high-power single-frequency fiber lasers (SFFLs) has continued up to the present day. Due to their compact structure [1], narrow linewidth [2], and high beam quality [3,4], they are widely used in nonlinear frequency conversion [5], coherent beam combining [6], and gravitational wave detection (GWD) [7]. Especially in the field of GWD, they show a higher output power and higher detection sensitivity in their measuring systems [7].…”