Highly stable graphene-assisted tunable dual-wavelength erbium-doped fiber laser

Generation of mode-locked states of conventional solitons and bright-dark solitons in graphene mode-locked fiber laser

This paper proposes a mode-locked fiber laser based on graphene-coated microfiber. The total length of the fiber laser resonant cavity is 31.34 m. Under the condition of stable output of bright-dark soliton pairs from the fiber laser, dual-wavelength tuning is realized by adjusting the polarization controller (PC), and the wavelength tuning range is 11 nm. Furthermore, the effects of polarization states on bright-dark solitons are studied. It is demonstrated that the mode-locking state can be switched between conventional solitons and bright-dark solitons in the graphene mode-locked fiber laser. Bright-dark soliton pairs with different shapes and nanosecond pulse width can be obtained by adjusting the PC and pump power.

Tunable mode-locked erbium-doped fiber laser based on a digital micro-mirror device

A tunable mode-locked erbium-doped fiber laser with a digital micro-mirror device (DMD) as the wavelength tuner and nonlinear amplifying loop mirror as the mode-locked device is proposed and experimentally demonstrated. The mode-locked pulse with the center wavelength of 1538-1565 nm continuously tunable is achieved. The average power of the output pulse is 1.028 mW, the pulse repetition frequency is 1.7 MHz, the pulse duration is 616 fs, and the single pulse energy is 0.6 nJ. By controlling the DMD, the center wavelength can be fine-tuned with the tuning accuracy of 0.07 nm. With the increase of the pump power, the traditional soliton pulse is transformed into a noise-like pulse (NLP), and the power of the NLP can reach 34 mW. This mode-locked process can work for a long time and is almost unaffected by the external environment. These results are very useful for applications where pulsed lasers with different wavelengths are needed.

A Stable Dual-wavelength Thulium-doped Fiber Laser at 1.9 μm Using Photonic Crystal Fiber

A stable dual-wavelength thulium-doped fiber laser operating at 1.9 μm using a short length of photonic crystal fiber (PCF) has been proposed and demonstrated. The photonics crystal fiber was 10 cm in length and effectively acted as a Mach-Zehnder interferometry element with a free spectral range of 0.2 nm. This dual-wavelength thulium-doped fiber laser operated steadily at room temperature with a 45 dB optical signal-to-noise-ratio.

Multiwavelength erbium-doped fiber laser based on graphene oxide

A multiwavelength erbium-doped fiber (EDF) laser based on graphene oxide (GO) has been proposed, to the best of our knowledge, for the first time, to generate an output of stable wavelengths. The structure mainly comprises a few layers of GO between two single-mode fibers incorporated into a capillary device and a Lyot comb filter. GO can show a good nonlinear optical effect, which is beneficial to suppress the mode competition caused by the EDF and stabilize the multiwavelength output. With assistance from the GO device, 11 stable simultaneous lasing signals with a power nonuniformity of about 1.5 dB are obtained. Wavelength spacing is about 0.42 nm and the linewidth of each wavelength is less than 0.07 nm.

Closely spaced dual-wavelength fiber laser using an ultranarrow bandwidth optical filter for low radio frequency generation

A dual-wavelength (DW) fiber laser with a closely spaced single longitudinal mode (SLM) output is proposed and demonstrated. The proposed fiber laser utilizes a conventional fiber Bragg grating with a center wavelength of about 1546.8 nm in conjunction with an ultranarrow bandwidth tunable optical filter to generate the desired DW SLM output. Observations with a very high resolution optical spectrum analyzer, which was capable of achieving resolutions up to 0.16 pm, revealed detailed spectral characteristics not characteristically seen before. A channel spacing of up to 58 nm was realized, and spacing as small as 2 pm was achieved. The minimum channel spacing and its resulting beat frequency are the narrowest observed yet to the best of our knowledge for a DW fiber laser at room temperature.