Nd-doped Fiber Laser Research Articles

Antiphase dynamics and polarization effects in the Nd-doped fiber laser.

The response of an Nd-doped optical fiber laser to modulation of the pump power reveals that the polarization of the laser light plays an important role in the linear and nonlinear dynamics of this laser. Experiments have been carried out under pulsed or sinusoidal modulation of the pump power as well as in the continuous-wave regime. Most of the observed phenomena may be interpreted in the framework of a theory of the two-mode laser in which each mode is associated with one polarization eigenstate of the laser. Effects such as the appearance of slow modes and antiphase behavior have also been observed. A model of a two-mode laser including spontaneous emission is theoretically and numerically analyzed. It reproduces well most of the experimental findings.

Wavelength tunability in a Nd-doped fiber laser with an intracavity polarizer

When an intracavity polarizer is introduced into a Fabry-Perot Nd-doped fiber laser, wide wavelength tunability is achieved either by rotating the polarizer or by varying, the fiber birefringence with an in-line polarization controller. The intracavity polariser also produces considerable line-narrowing. A model based on birefringence dispersion is proposed. >

Frequency-modulated cavity-dumped Nd-doped fiber laser

A cw-pumped Nd-doped single-mode double-clad fiber laser coiled around a resonant piezoelectric ceramic ring and coupled to an empty external cavity with strong feedback is described. Intensity laser pulses with durations in the 1-2-micros range are observed as the pump power or the ring drive voltage is increased, yielding peak powers as much as 25 times greater than average powers. The effect is attributed to strong phase modulation of the fiber laser by the piezoelectric ring, which induces FM laser oscillation. The external cavity acts as a frequency-dependent reflector, thus effectively cavity dumping the fiber laser as the oscillation frequency is swept through the narrow transparent windows of the external cavity.

Spectrum stability of a broadband 1060 nm Nd-doped fibre laser

Measurements of the spectrum dependence on temperature of a broadband diode-pumped fibre laser, targeted as a source for high grade fibre gyroscopes is reported. With the proper choice of pump wavelength, the temperature of this source need only be stabilised to 0.1°C for a mean laser wavelength stability of 1 ppm, compared to 0.003°C for a superluminescent diode source.

Diode-pumped 1.36 μm Nd-doped fibre laser

Laser emission has been observed at 1.363μm on the 4F3/2−4I13/2 transition from a diode-pumped Nd-doped phosphate glass single-mode fibre. Normally, this transition is strongly suppressed in an oxide glass host due to excited state absorption effects which reduce the efficiency of this transition. We observe both the lowest lasing threshold (5 mW) and the highest slope efficiency (10.8%) reported for a fibre laser in the 1.3 μm spectral region.

All-solid-state passively Q-switched mode-locked Nd-doped fiber laser

We report the generation of Q-switched mode-locked pulses from a Nd-doped fiber laser that uses a solid-state solution of BDN-I dye as the saturable absorber and is pumped by a GaAlAs laser diode. For an absorbed pump power of 110 mW, pulses of 8-nsec duration at a repetition rate of 14 MHz can be generated under an 800-nsec-wide Q-switched envelope at a repetition rate of 10 kHz, yielding an average output power of 8 mW near 1.06 μm. This corresponds to approximately 9 W of peak power in the main mode-locked pulse.

Application-Specific Optical Fibres Manufactured from Multicomponent Glasses.

AbstractSpecial fibres have been fabricated to demonstrate the potential of using multicomponent glass materials for sensors, devices and fibre lasers. High nonlinearity and large Verdet constants are confirmed for lead-silicate glass fibres. Nonlinear effects such as second harmonic generation (SHG), third harmonic generation (THG), electro-optic (EO) Kerr effect and optical switching are observed for F7 core glass fibres. Compound glasses are investigated as host glasses for fibre lasers and amplifiers. An all glass cladding pumped Nd-doped fibre laser from compound glassses is characterized.

Measurements of fibre laser losses via relaxation oscillations

We describe a simple method for measuring fibre laser losses. The method is based on including relaxation oscillations by modulating the laser gain. From the oscillation frequency and known fibre parameters a loss figure can be extracted. Loss measurements performed on a Nd-doped fibre laser are presented.

High-efficiency Nd-doped fibre lasers using direct-coated dielectric mirrors

The letter presents an Nd-doped silica single-mode fibre laser with dielectric mirrors coated directly on to the fibre endfaces. The LD-pumped fibre laser had a CW output power of more than 4mW, a threshold power of 1.51 mW and a slope efficiency of 55%. The theoretically predicted values and experimental values of the laser characteristics are very similar owing to a negligibly small excess cavity loss.