Narrow linewidth CW and Q-switched erbium-doped fibre loop laser

Abstract

The authors report the operation of a single-frequency, diode-pumped laser in CW operation with a linewidth of 10kHz, which provides a prelase for a narrow linewidth Qswitched laser. This was achieved by incorporating an unpumped low Er 3+ -doped fibre. In Q-switched operation, a linewidth of less than 60MHz is reported for pulses of 1µs at a repetition rate of 960 Hz.

An All‐Optical, Actively Q‐Switched Fiber Laser by an Antimonene‐Based Optical Modulator

“…These benefits are of vital importance to a variety of practical applications, for example, industrial material processing and optical information transmission, where the output laser pulses require timing coincidence with input electric pulses. Traditionally, actively Q‐switched fiber lasers are implemented by bulk electro‐optical or acoustic‐optic modulators which are typically expensive, structurally complicated, and optically narrowband. Moreover, these electrically‐modulated Q‐switchers seem to be unsuitable for all‐optical applications in future, including all‐optical network and computing.…”

All‐fiber actively Q‐switched Er3+/Yb3+ co‐doped ring laser

“…Passively Qswitched lasers have very simple structures and can supply short and powerful pulses operation, but the repetition frequency can not be modified with independence of other operation parameters [1][2][3]. Research has been undertaken to realized-stable repetition frequency by using actively Q-switched (AQ) fiber laser, such lasers have very good performance, but their Q-switching operations are achieved by the use of acousto-optics modulators [4], electro-optics modulators [5], or an intensity modulator [6], which can not only degrade the beam quality and the laser stability, but increase the complication design of a practical device.…”

“…In recent years, there has been growing interests in investigating electromagnetic band gap (EBG) structures, and diversified kinds of EBG structures have been suggested for the applications in the electromagnetic and antenna community [1][2][3][4][5][6][7]. Because the period of EBG lattices has to be a half-wavelength at the band-gap frequency, practical application of EBG structures usually has difficulty in accommodating its physical size, and realizing compact size for EBG structure is one of the most important issues to be solved.…”

“…Recently high impedance surfaces (HIS), as a successful compact EBG structure consisted of small metal pads with grounding vias, have been exclusively investigated [5][6][7]. However, in some practical applications, such as in antenna array, the spacing of neighboring antenna element has to be less than a half wavelength of operating frequency, the Sievenpiper HIS structure is still too large to be fixed on the antenna.…”

Applications of In–Fiber Acousto–Optic Devices

“…On the other hand, active Q-switching is independently and accurately controlled by an electrical signal, which triggers the modulator. The bulk approach, such as electro-optic (Kee et al, 1998) or acousto-optic modulators (Álvarez-Chávez et al, 2000), is not adapted to compact fiber laser systems required nowadays; further they have large optical coupling losses and stringent alignment requirements. For these reasons, the all-fiber approach is of permanent interest, being advantageous in terms of cost, loss, packaging, robustness, and simplicity.…”