K.I. Martin

3 W of single-frequency output at 532 nm by intracavity frequency doubling of a diode-bar-pumped Nd:YAG ring laser.

A beam-shaped 20-W diode bar has longitudinally pumped a Nd:YAG laser in a ring configuration. Unidirectional single-frequency operation is enforced by a Faraday rotator. Intracavity frequency doubling with a KTP crystal has produced 3 W of stable single-frequency TEM00 output at 532 nm.

SELF-SUPPRESSION OF AXIAL MODE HOPPING BY INTRACAVITY SECOND-HARMONIC GENERATION

Intracavity second-harmonic generation (SHG) in a single-frequency laser has an associated loss for adjacent nonlasing modes, from sum-frequency generation, that is greater than the loss from SHG for the lasing mode. Mode hopping is thereby suppressed, as the lasing mode dominates neighboring modes. We have investigated this behavior in a Nd:YAG laser with LBO intracavity frequency doubler, obtaining frequency tuning over more than 80 axial mode spacings, without mode hopping.

High-power single-frequency operation, at 1064 nm and 1061.4 nm of a Nd:YAG ring laser end-pumped by a beam-shaped diode bar☆

A Nd:YAG laser having a ring configuration, with Faraday rotator to provide unidirectional operation has been end-pumped by a single 20 W diode bar equipped with a beam-shaper. A single-frequency TEMoo output of 5.4 W is achieved at 1064 nm. Using a thin intracavity etalon for wavelength selection, a single-frequency output of 4.2 W is obtained on the 1061.4 nm transition

Limitations imposed by spatial hole burning on the single-frequency performance of unidirectional ring lasers

Residual spatial-hole-burning in a unidirectional ring laser can limit the maximum power available in a single-frequency. These effects have been modelled numerically and verified experimentally in Nd:YAG and Nd:YLF lasers. For convenience, an analytical expression for maximum single-frequency power has also been developed for use in designing ring lasers.

Increased single-frequency power from end-pumped ring lasers by pump beam displacement

End-pumped unidirectional ring lasers often suffer some degree of residual spatial hole burning, where a standing-wave region overlaps the pumped region. By non-concentric pumping this overlap can be reduced, thus increasing the output power level at which single frequency operation can be maintained. Experimental results show a factor of 2 to 3 improvement in single-frequency performance for only a small drop in output power.

Mode-hop-free tuning in high-power intracavity-frequency-doubled Nd:YAG and Nd:YLF ring lasers

By simple cavity length adjustment, continuous, mode-hop-free tuning over many axial-mode spacings has been observed in efficient, intracavity-frequency-doubled, single-frequency Nd:YAG and Nd:YLF ring lasers generating multiwatt output powers at 532nm and 526.5nm

Suppression of Mode-Hopping in a Single-Frequency Intracavity-Frequency-Doubled Nd:YAG Ring Laser.

Suppression of mode-hopping in a high-power intracavity-frequency-doubled Nd:YAG ring laser has been observed allowing continuous tuning over ~80 axial mode spacing. An explanation for this behaviour is proposed