Frequency noise of distributed Bragg reflector single-frequency fiber laser.

We investigated the frequency noise in the distributed Bragg reflector single-frequency fiber laser (DBR-SFFL) theoretically and experimentally. A complete theoretical analysis is demonstrated by considering the energy-transfer upconversion (ETU) process and establishing linkages between the frequency noise and the relative intensity noise (RIN) of the DBR-SFFL. The experimental results of the diverse DBR-SFFLs in different working conditions are in good agreement with the theoretical analyses.

Self-injection locked and semiconductor amplified ultrashort cavity single-frequency Yb-doped phosphate fiber laser at 978 nm.

Based on a self-injection locking scheme and the nonlinear amplification effect of a semiconductor optical amplifier, a low intensity noise amplified ultrashort cavity single-frequency fiber laser at 978 nm is demonstrated with a final output power of > 230 mW and a broad temperature range of > 15 °C for single-longitudinal-mode operation. The effective cavity length of the fiber oscillator is less than 6 mm, comprising a 3.5-mm-long highly Yb-doped phosphate fiber and a pair of fiber Bragg gratings.

Ultra-narrow linewidth full C-band tunable single-frequency linear-polarization fiber laser.

An ultra-narrow linewidth full C-band tunable single-frequency linear-polarization fiber laser based on self-injection locking has been demonstrated. By the use of a tunable narrow-band fiber Fabry-Perot interferometer, the laser wavelength could be flexibly tuned from 1527 to 1563 nm with linewidths of < 700 Hz. The laser frequency noise is less than 40 dB re Hz/Hz at low frequencies (< 100 Hz) and reaches -5 dB re Hz/Hz at around 25 kHz.

Linewidth suppression mechanism of self-injection locked single-frequency fiber laser.

Linewidth suppression mechanism of the self-injection locked single-frequency fiber laser (SFFL) is investigated theoretically and experimentally. An analytical model based on the semi-phenomenological approach is built up to characterize the optical feedback in SFFL. According to the theoretical prediction, the linewidth tends to be reduced with longer external cavity photon lifetime.

Dual-wavelength passively q-switched single-frequency fiber laser.

We propose a compact dual-wavelength Q-switched single-frequency fiber laser based on a 17-mm-long home-made highly Er/Yb co-doped phosphate fiber (EYDPF) and a semiconductor saturable absorber mirror (SESAM). The short cavity length and a polarization-maintaining fiber Bragg grating (PM-FBG) ensure that only one longitudinal mode is supported by each reflection peak. The maximum pulse energy of more than 34.

Short all Tm-doped germanate glass fiber MOPA single-frequency laser at 1.95 μm.

Based on heavily Tm-doped germanate glass fibers (TGFs), a short all-TGF MOPA laser system with uniform core parameters in each stage was demonstrated. An 11.7 W stable single-frequency laser at 1.

Broad-bandwidth near-shot-noise-limited intensity noise suppression of a single-frequency fiber laser.

A significant broad-bandwidth near-shot-noise-limited intensity noise suppression of a single-frequency fiber laser is demonstrated based on a semiconductor optical amplifier (SOA) with optoelectronic feedback. By exploiting the gain saturation effect of the SOA and the intensity feedback loop, a maximum noise suppression of over 50 dB around the relaxation oscillation frequencies and a suppression bandwidth of up to 50 MHz are obtained. The relative intensity noise of -150  dB/Hz in the frequency range from 0.

Linearly frequency-modulated pulsed single-frequency fiber laser at 1083 nm.

A linearly frequency-modulated, actively Q-switched, single-frequency ring fiber laser based on injection seeding from an ultra-short cavity is demonstrated at 1083 nm. A piezoelectric transducer is employed to obtain linearly frequency-modulating performance and over 1.05 GHz frequency-tuning range is achieved with a modulating frequency reaching tens of kilohertz.