1,720,964 research outputs found
Explanation of the mechanism for acousto-optically induced unidirectional operation of a ring laser
No full textUnidirectional and hence single frequency operation of ring laser is generally achieved using an intracavity Faraday isolator. An alternative technique, demonstrated recently for Nd:YAG, dye, and Ti:sapphire ring lasers, makes use of the acousto-optic effect (AO) effect
Unidirectional operation of a ring laser via the acousto-optic effect
No full textTwo different techniques described for enforcing unidirectional operation of a ring laser using the acoustooptic effect. A simple quantitative explanation for each mechanism is presented, together with a detailed analytical model which allows the difference in loss for the counter-propagating beam to be calculated. Experimental results which confirm the validity of the models are also presented. The application of these techniques for single frequency CW and Q-switched operation of miniature solid-state lasers is discussed and, based on the analytical model, strategies for optimising the design of acoustooptic modulators and ring resonators are considered
Novel beam shaping technique for high power diode bars
No full textUsing a novel beam shaping technique. a diode bar output has been focused to a spot of 150µm diameter. Preliminary results for efficient end-pumping of a Nd:YAG laser are reported
Diode laser bar beam shaping technique
No full textA high power diode bar has been focused to a spot of <150µm diameter using a novel beam shaping technique. The implications of this result for efficient end-pumping of solid-state lasers are discussed
Single frequency CW and Q-switched operation of a diode-pumped Nd:YAG 1.3µm ring laser
No full textThe use of an acousto-optic modulator in a ring laser to enforce unidirectional and hence single-frequency operation has been extended to the 1.3µm lines in Nd:YAG. We have also been able to obtain stable simultaneous operation on a single frequency in each of the 1.319µm and 1.338µm transitions either CW or Q-switched. The mechanism behind this behaviour is described and implications for other laser systems are discussed. When operated single frequency, up to 155 mW of CW output is produced, and 30 pJ, 40 nsec Q-switched pulses have been obtained
Unidirectional operation of a ring laser by resonating the diffracted beams in a travelling-wave acousto-optic modulator
No full textEnforcing unidirectional operation of a ring laser is an attractive way to obtain a single frequency output from a solid-state laser. Recent work suggests that a reliable way to achieve unidirectional operation is by using an intracavity traveling-wave acousto-optic (AO) modulator. The nonreciprocal behavior of this device is due to its traveling-wave nature, which causes the counterpropagating beams to suffer different diffraction losses - a consequence of the Bragg condition being satisfied at different angles of incidence for the counterpropagating beams
Acousto-optically induced unidirectional operation of a ring laser a feedback mechanism
No full textA second mechanism for acousto-optically induced unidirectional operation of a ring laser has been identified and demonstrated experimentally. The mechanism involves feeding back the diffracted wave thus restoring to its original frequency and direction via a second diffraction from the travelling-wave acousto-optic modulator. Since the feedback resonance condition is different for the two counter-propagating waves of the ring laser they experience a loss difference which results in unidirectional operation via this method a very large loss difference can be achieved with negligible insertion loss
Stable high repetition rate single frequency Q-switched Nd:YAG ring laser
No full textReliable single-frequency operation of a diode-pumped, Q-switched, Nd:YAG ring laser at high repetition frequencies up to 25kHz has been achieved by active stabilisation of the prelase power. Average powers of 250mW have been obtained for a 1.2 watt diode pump
Stable two-mode operation of a unidirectional ring laser via controlled spatial hole-burning
No full textUnidirectional ring lasers are commonly used to eliminate spatial hole-burning in the gain medium and hence allow single-axialmode operation of the laser. A number of applications require two (or more) laser outputs, each of which comprises a single frequency, i.e., not accompanied by adjacent modes, and which are stable in frequency and amplitude. Here we report a technique for achieving this, either cw or Q-switched, in a unidirectional ring laser. The technique is based on the presence of a small degree of beam overlap in the gain region of the laser
The effect of residual spatial hole burning in unidirectional ring lasers
No full textA convenient way to achieve efficient single frequency output from a homogeneously-broadened solid-state laser is by using a resonator configuration in which spatial hole burning is avoided. One of the most frequently used techniques employs a unidirectional ring resonator configuration. This approach has proved very successful, particularly with miniature diode-pumped solid-state lasers, and has led to a number of reliable single frequency laser devices
- …
