0000000000117335
AUTHOR
E. Hernández-escobar
Actively mode-locked all-fiber laser by 5 MHz transmittance modulation of an acousto-optic tunable bandpass filter
Active mode-locking of an all-fiber ring laser by transmittance modulation of an in-fiber acousto-optic tunable bandpass filter (AOTBF) is reported. Cavity loss modulation is achieved by full acousto-optic mode re-coupling cycle induced by standing flexural acoustic waves. The modulator permits the implementation of 28 dB of nonresonant light suppression, 1.4 nm of modulation bandwidth, 74% of modulation depth and 4.11 dB of optical loss in a 72.5 cm-long all-fiber configuration. The effects of the modulated AOTBF on the laser performance are investigated. Transform-limited optical pulses of 8.8 ps temporal width and 6.0 W peak power were obtained at 4.87 MHz repetition rate.
Q switching and mode locking pulse generation from an all-fiber ring laser by intermodal acousto-optic bandpass modulation
Q-switched and mode-locked (QML) pulse generation from an all-fiber ring laser based on intermodal acousto-optic bandpass modulation is reported. The modulator relies on full-acousto-optic mode re-coupling cycle induced by a standing flexural acoustic wave, with a transmission response that is controlled by amplitude modulation of the acoustic wave signal. The Q factor of the cavity is controlled by a rectangular pulse wave with variable frequency and duty cycle, whereas mode locking is achieved by amplitude modulation derived from a standing flexural acoustic wave. The best QML pulses were obtained at 0.5 kHz repetition rate, with a pump power of 549.2 mW, at the optical wavelength of 1568…
The nonlinear optical loop mirror: soliton and noise-like pulse emission in a figure-eight fiber laser
In this article, a symmetrical nonlinear optical loop mirror (NOLM) exhibiting a polarization-dependent transmission is evaluated to generate optical pulse emission in a figure-eight fiber laser in the soliton and noise-like pulse (NLP) regimes. The NOLM structure relies on a 50:50 fiber coupler, a loop with highly twisted single-mode optical fiber and a quarter-wave retarder (QWR) to break the polarization asymmetry. The pulse operation regime is determined by properly adjusting the NOLM low-power transmission, which is easily realized by the rotation of the QWR angle. Soliton pulses of 1.48 ps pulse duration and peak power of 18 W were observed with a peak to peak separation of 1.25 µs, c…
Broadband tuning of a long-cavity all-fiber mode locked Thulium-doped fiber laser using an acousto-optic bandpass filter
A long-cavity passively mode-locked thulium-doped all-fiber laser is reported incorporating a tapered acousto-optic tunable bandpass filter (AOTBF). The operation of the AOTBF relies on the intermodal coupling between core and cladding modes when a flexural acoustic wave propagates along an 80-microm tapered fiber. The filter works in transmission and exhibits a 3-dB bandwidth of 9.02 nm with an insertion loss of 3.4 dB. The laser supports ultrashort pulse generation at a low repetition rate of 784.93 kHz. Optical pulses with 2.43 nm of optical bandwidth and 2.1 ps pulse duration were obtained in a broad tuning range from 1824.77 to 1905.16 nm.
Flat supercontinuum generation pumped by amplified noise-like pulses from a figure-eight erbium-doped fiber laser
The conditions to obtain noise-like pulses (NLPs) from a figure-eight fiber laser (F8L) and their application for supercontinuum (SC) generation in the anomalous dispersion regime are reported. The F8L is designed to remove the undesired low-intensity background radiation from pulse emission, generating NLPs with a 3 dB spectral bandwidth of 17.43 nm at the fundamental repetition frequency of 0.8 MHz. After amplification, NLPs reach a maximum average power of 9.2 mW and 123.32 nm spectral bandwidth. By controlling the amplifier pump power, flat SC generation is demonstrated through both a 800 m long spool of SMF-28 fiber and a piece of 5 m long highly nonlinear optical fiber. The results de…