Narrowband 10-ps-class mode-locked erbium-doped fiber laser oscillator

We demonstrate a narrowband erbium-doped fiber (EDF) laser oscillator having a linear cavity based on the design of bulk laser oscillators mode-locked by a semiconductor saturable absorber mirror (SESAM) and out coupled by a fiber Bragg grating. The EDF laser oscillator has an average power of 7.06 +/- 0.04 mW with a 3 dB bandwidth of 0.37 nm and a pulse duration of 12 ps at a repetition rate of 50.47 MHz. A pulse energy of 140 pJ is the highest ever reported in SESAM mode-locked EDF laser oscillators with a nearly Fourier-limited pulse duration demonstrating power scalability of a bulk laser and compactness of a nearly all-fiber laser. The repetition rate has a free-running fluctuation of only 312 Hz over 7 h of operation making it a promising light source for application to laser spectroscopy. The long pulse duration makes this EDF laser oscillator a suitable source for seeding a high-average-power amplifier using a large mode-area photonic crystal or tapered gain fiber without the need of pulse stretching. Moreover, this laser oscillator could be an alternative solution to the development of complicated bulk narrowband laser sources suitable for building an ion trap for application to quantum computing.