All-Polarization-Maintaining Passively Mode-Locked Erbium-Doped Fiber Laser Based on a WDM-Isolator-Tap Hybrid Device

We present an all-polarization-maintaining (PM) compact passively mode-locked fiber laser using a PM wavelength division multiplexer (WDM)-isolator-tap (WIT) hybrid device with good stability. Compared with inserting the WDM, isolator, and tap into a traditional cavity, only a PM WIT device could simultaneously inject the pump light into the cavity, control the unidirectional operation of the ring cavity, and provide the lasing output from the cavity. With this simple structure, the system generated a soliton pulse of 1.085 ps at 17.77 MHz, with a 54 dB signal-to-noise ratio (SNR).