Andrew Finch

Low-threshold, cw, all-solid-state Ti:Al 2 O 3 laser

A cw Ti:A1(2)O(3) ring laser with a threshold power of 119 mW is demonstrated. It provides a tunable source of single-frequency, diffraction-limited radiation that is suitable for injection seeding. The Ti:A1(2)O(3) laser is operated with a diode-laser-pumped, frequency-doubled, Nd:YAG laser as the sole pump source.

All-solid-state, high-power, deep-UV laser system based on cascaded sum-frequency mixing in CsLiB 6 O 10 crystals

We report on an efficient use of CsLiB6O10 (CLBO) crystals employed for an all-solid-state deep-UV laser system operated at 5 kHz. We obtained greater than 3 W of UV radiation around 242 nm by mixing the 349-nm third harmonic of a Nd:YLF laser with the tunable output from a Ti:sapphire laser in a CLBO crystal. This UV radiation was subsequently mixed with the residual 1047-nm output from the Nd:YLF laser in a second CLBO crystal. The system produced 1.5 W of deep-UV radiation at 196.3 nm, which is, to our knowledge, the highest deep-UV power below 200 nm generated in a nonlinear optical crystal. Additionally, the bandwidth of both outputs was estimated to be less than 200 MHz.

High-power narrowband DUV laser source by frequency mixing in CLBO

We describe an all solid-state, high power, deep-UV (DUV) source based on sum-frequency mixing (SFM) of two single- frequency laser outputs. The system consists of a CW diode- pumped, Q-switched Nd:YLF laser operating at 1047 nm, a Ti:sapphire laser at 785-nm, and cascading SFM stages. Both laser sources are configured with an injection-seeded oscillator followed by amplifier to produce high power, single-frequency, TEM00 outputs. The third harmonic of Nd:YLF MOPA is mixed with the output from Ti-sapphire MOPA to generate the first UV, which is used for the second mixing with the residual fundamental output to generate the DUV radiation. CLBO crystal is employed for each SFM process. The system produced UV pulses at 241.6 nm with 3.4 W, and also DUV at 196.3 nm with 1.5 W of average powers at a 5-kHz pulse- repetition rate. The linewidth of the DUV output was measured to be less than 0.05 pm.

Properties and applications of CLBO

Summary form only given. In this talk various information on the properties of CsLiB/sub 6/O/sub 10/ (CLBO) and the latest life test data at high repetition rate are provided for applications in reliable UV lasers.

2.5-Watt single-frequency CW Tm,Ho:YLF ring laser

In this paper we describe the design and performance of a diode-laser-pumped, cw Tm,Ho:YLF ring laser. Single frequency operation is obtained by using an acousto-optic modulater as a unidirectional device. The laser has produced over 2.5 W of single-frequency output power at 2.065 pµm for an incident pump power of 14 W. Using a 100-µm fused silica etalon, the laser was tuned from 2.0537 - 2.0671 µm.

Watt-level DUV generation by solid state laser for lithography

The first all-solid-state laser system generating 1 W of 196 nm light at a 5-kHz pulse-repetition rate has been developed. The laser system consists of a Neodymium:Yttrium Lithium Fluoride maser oscillator power amplifier operating at 5 kHz, a single-frequency, gain-switched Titanium:sapphire laser, and additional frequency conversion stages utilizing nonlinear crystal such as Cesium Lithium Borate grown by USHIO and Lithium Triborate. The performance of each system component will discussed as well as the novel pathway employed to reach 196 nm.

Development of advanced solid-state lasers for Iidar

In Ref. 5 we have shown that the thermal quenching can induce a rolloff of the small signal gain as the pump power increases. As the gain and the energy per pulse in Q-switched operation are bound together, we can attribute the bad performances of Cr:LiSAF to higher quenching of fluorescence. In conclusion, Cr:LiSGaF is more suitable than Cr:LiSAF for the production of tunable pulses at high repetition rate under diode pumping.