M. Hofer

Nonlinear amplifying loop mirror.

A novel device arrangement for all-optical switching that permits efficient exploitation of waveguide nonlinearities is discussed. It is based on a long optical fiber loop mirror with an integral short asymmetrically located optical amplifier. The device performance is demonstrated by using a Nd(3+)-doped fiber amplifier. Switching is obtained for peak signal powers of less than 1 W and an amplifier pump power of 10 mW.

Mode locking with cross-phase and self-phase modulation.

Cross-phase and self-phase modulation are used for self-sustained mode locking of a high-power neodymium glass fiber laser. Stable pulses with a FWHM as short as 70 fs and pulse energies of as much as 1 nJ are generated at a wavelength of 1.064 microm.

Additive-pulse-compression mode locking of a neodymium fiber laser.

The generation of bandwidth-limited shoulder-free 125-fsec pulses by additive-pulse-compression mode locking of a neodymium glass laser is described. An all-fiber nonlinear amplifying loop mirror is employed as a fast saturable absorber and permits stable pulse generation under the condition of large pulse shaping in the cavity.

42-fs pulse generation from a mode-locked fiber laser started with a moving mirror.

Passive mode locking initiated with a moving mirror is demonstrated in a neodymium fiber laser for what is to our knowledge the first time. Near-bandwidth-limited pulses with a width of 42 fs and energies as high as 1 nJ are generated.

Self-starting diode-pumped femtosecond Nd fiber laser

A self-starting passively mode-locked diode-pumped neodymium fiber laser with a semiconductor antiresonant Fabry-Perot saturable absorber (A-FPSA) is demonstrated for the first time to our knowledge. Mode locking can be initiated and maintained by the semiconductor absorber, and pulse durations down to 260 fs are routinely obtained. Alternatively, shorter pulses (60 fs) were generated by exploition of nonlinear polarization evolution in the fiber (in combination with a stronger pump source) where the A-FPSA simply initiates the pulse-forming process.

Regenerative Nd:glass amplifier seeded with a Nd:fiber laser

Wavelength tuning and broad-bandwidth operation of a passively mode-locked Nd:fiber laser is demonstrated at 1060 microm. The oscillator pulses are used to seed a bulk regenerative Nd:glass amplifier, and 300-fs transformlimited pulses with an energy of 10 microJ are obtained after 31 round trips at a repetition rate of 500 Hz.

Active mode locking of a neodymium-doped fiber laser using intracavity pulse compression.

Active mode locking of a Nd(3+)-doped fiber laser with piezoelectrically induced Raman-Nath diffraction modulation is demonstrated. By using intracavity pulse compression, stable pulses of 2.4-psec length are generated at a wavelength of 1054 nm.

Modelocking of a Nd-fiber laser at 920 nm

Abstract We report mode-locked operation of a Nd-fiber laser at a wavelength of 920 nm. The moving mirror technique was used as a starting mechanism and mode-locking was self-sustaining by nonlinear polarization evolution. Nearly transform limited pulses of 53 fs duration with output energies of 500 pJ were generated.

High-power neodymium soliton fiber laser that uses a chirped fiber grating

The use of a highly chirped fiber Bragg grating for dispersion compensation in a self-starting passively mode-locked neodymium soliton fiber laser is demonstrated for the first time to our knowledge. By employing an appropriately designed saturable absorber as the mode-locking element and limiting polarization-dependent loss in the cavity, we obtain polarization-insensitive operation of the laser, and no intracavity polarization controllers are required for its optimization. The laser generated bandwidth-limited pulses of 6-ps duration with output energies as high as 1.25 nJ.

Widely tunable femtosecond neodymium fiber laser

Continuous tuning of a mode-locked Nd3+ fiber laser over 75 nm is reported. This wide tuning range, which extends over more than twice the FWHM gain bandwidth of Nd:glass, is achieved by optimization of the reflection characteristics and the band-gap energy of the multiple-quantum-well semiconductor saturable absorber. The pulse duration achieved is 300–400 fs over the entire tuning range.