We demonstrate a compact and low-cost all-fiber-based locking setup for frequency-noise suppression of a 420 nm external-cavity diode laser. Frequency noise reduction in the 100 Hz to 800 kHz range is demonstrated up to 40 dB associated with a linewidth narrowing from 850 kHz to 20 kHz for 10 ms integration time. This simple locking scheme might be implemented for a large range of wavelengths and can be integrated on a small footprint for embedded applications requiring narrow linewidth blue laser diodes.
View Article and Find Full Text PDFWe realize a fiber Bragg grating InGaN-based laser diode emitting at 400 nm and demonstrate its high coherency. Thanks to the fabrication of a narrowband fiber Bragg grating in the near-UV, we can reach single-mode and single-frequency regimes for the self-injection locked diode. The device exhibits 44 dB side-mode suppression ratio and mW output power.
View Article and Find Full Text PDFWe investigate the relative intensity noise (RIN) properties of a multi-Stokes Brillouin fiber ring laser. We experimentally analyse the intensity noise of each Stokes wave and study the noise dynamics of the cascaded Brillouin scattering process. We observe up to 20 dB/Hz intensity noise reduction compared to that of the RIN input pump laser.
View Article and Find Full Text PDFWe provide numerical verification of a feed-forward, heterodyne-based phase noise reduction scheme using single-sideband modulation that obviates the need for optical filtering at the output. The main benefit of a feed-forward heterodyne linewidth reduction scheme is the simultaneous reduction of the linewidth of all modes of a mode-locked laser (MLL) to that of a narrow-linewidth single-wavelength laser. At the heart of our simulator is an MLL model of reduced complexity.
View Article and Find Full Text PDFWe report on the frequency noise reduction performance of a feed-forward technique. The Letter is based on frequency noise measurements that allow the spectral response of the feed-forward phase noise correction to be determined. The main limitation to the noise compensation is attributed to the local oscillator flicker noise and the noise added by the optoelectronic loop elements.
View Article and Find Full Text PDFA compact second-order Stokes Brillouin fiber laser made of microstructured chalcogenide fiber is reported for the first time. This laser required very low pump power for Stokes conversion: 6 mW for first order lasing and only 30 mW for second order lasing with nonresonant pumping. We also show linewidth-narrowing as well as intensity noise reduction for both the 1st and 2nd order Stokes component when compared to that of the pump source.
View Article and Find Full Text PDFRelative intensity noise and frequency noise have been measured for the first time for a single-frequency Brillouin chalcogenide As38Se62 fiber laser. This is also the first demonstration of a compact suspended-core fiber Brillouin laser, which exhibits a low threshold power of 22 mW and a slope efficiency of 26% for nonresonant pumping.
View Article and Find Full Text PDFBistabilities between a steady (or pulsating, chaotic) and different pulsating regimes are investigated for an optically injected semi-conductor laser. Both numerical and experimental studies are reported for continuous-wave single-mode semiconductor distributed-feedback lasers emitting at 1.55 microm.
View Article and Find Full Text PDFWe describe an all-fiber ytterbium-doped laser followed by a double-stage ytterbium-doped double-clad fiber amplifier of 10-W output power for helium pumping. Different cavity designs are investigated with the goal of achieving high-power multimode emission at 1083 nm, wavelength tunability over the helium absorption bands, and linewidth envelope control over the range 1-3 GHz. We point out the domains with unstable output power and discuss their origin.
View Article and Find Full Text PDF