Shirin M. Giffin

Solid state dye lasers based on 2-hydroxyethyl methacrylate and methyl methacrylate co-polymers

Abstract The laser performance of a range of solid state dye lasers based on rhodamine 590-doped co-polymers of 2-hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) has been investigated. The optimisation of preparation conditions, including polymerisation initiator and solvent for dye delivery is discussed in detail. Laser efficiency is compared for different polymeric hosts and dye concentrations with a range of output couplers, cavity lengths and repetition rates. Passive and dynamic loss have been determined for each host medium. Laser efficiencies of optimised polymers are among the highest reported for rhodamine 590-doped solid state dye lasers under these operating conditions. Highest slope efficiency of 35% and lowest threshold fluence of 0.06 J cm −2 were obtained with dimethyl sulphoxide (DMSO) additive in MPMMA at 10 Hz repetition rate.

Tunable visible solid-state lasers based on intracavity frequency doubling of Cr:forsterite in KTP

Broadband tunability in the yellow-red region is obtained by use of intracavity type II second-harmonic generation of gain-switched Cr:forsterite lasers in KTiOPO(4) . An operating wavelength range of 67 nm, from 587 to 654 nm, is obtained. Second-harmonic energy of almost 1 mJ is achieved at a peak wavelength of 620 nm. A measured factor-of-34 enhancement in acceptance angle is obtained with broadband harmonic generation. Frequency doubling is optimized with respect to the Cr:forsterite pump and laser parameters.

Tunable visible solid-state lasers based on second-harmonic generation of LiF:F(2) in potassium titanyl phosphate.

A new broadly tunable visible solid-state laser is reported. Wavelengths between 550 and 610 nm are generated by intracavity frequency doubling of tuned and free-running room-temperature pulsed LiF:F(2)(-) lasers in potassium titanyl phosphate. Second-harmonic energy of 1.3 mJ has been achieved, corresponding to a fundamental-to-second-harmonic conversion efficiency of 20%. Operation is optimized with respect to LiF:F(2)(-) laser parameters.

Efficient, high photostability, high brightness, co-polymer solid state dye lasers

Abstract We report an investigation of the laser beam quality, efficiency and photostability of rhodamine 590 solid state dye lasers with hosts based upon 2-hydroxyethylmethacrylate and methylmethacrylate P(HEMA:MMA) co-polymers and modified methylmethacrylate (MPMMA) polymers with ethanol and dimethylsulphoxide additives. Highest efficiencies were obtained with MPMMA, with slope efficiencies of up to 44% (corresponding to 61% optical-optical conversion) measured for ethanolic MPMMA. P(HEMA:MMA) hosts gave superior photostability, with the highest normalized photostability of 240 GJ mol−1 obtained for a P(HEMA:MMA) 1:1 rod. A simple resonator has been used to compensate the effects of thermal lensing and pump mode-mismatch, resulting in optimized beam quality for MPMMA lasers.

Tunable yellow–green laser based on second harmonic generation of LiF:F−2 in KTP

A yellow–green solid-state laser source based on frequency- doubling of a room temperature LiF:F−2 laser in KTP is reported. Second harmonic generation of free-running and prism-tuned pulsed lasers has been characterized. Tunable operation between 555 and 595nm was obtained, with a conversion efficiency of 7.5% for the free-running laser, and up to 4% for the prism-tuned configuration. The angular bandwidth of 60milliradians exceeded the theoretical value by a factor of 3.5. A flattened tuning curve in the visible region was obtained through enhanced conversion efficiency in the wings of the LiF:F−2 laser tuning range.

Tunable visible solid-state lasers based on second-harmonic generation of LiF:F/sub 2//sup -/ in KTP

Tunable green-yellow lasers are required for a wide range of applications. However, the current solid-state sources in this region, optical parametric oscillators (OPOs) and solid-state dye lasers, have limitations. Operating lifetimes of solid-state dye lasers remain extremely short, and OPOs place strict requirements on the spatial and spectral properties and pointing stability of the pump laser. We investigate a new solid-state route to a tunable visible laser, which minimizes these problems. Efficient operation with broadband tunability through the green-orange region is demonstrated using intracavity second-harmonic generation of room-temperature LiF:F/sub 2//sup -/ lasers in KTP. The unique 1070-nm to 1310-nm operating wavelength range of LiF:F/sub 2//sup -/ makes it the only solid-state laser with the potential for tunable second-harmonic generation across the entire 550-nm to 650-nm region.

Highly efficient and photostable perylene orange doped polymer and co-polymer lasers

Summary form only given. Solid-slate dye lasers (SSDLs) offer a simple, efficient and cost-effective means of providing wavelength agility from frequency-doubled and tripled Nd lasers. However, significant improvements must be made in matching new host media to existing dyes and to emerging dyes such as the pyrromethene and perylene series. Of particular interest are new copolymer hosts, which can provide enhanced polymer cross-linking and broad dye compatibility, and the dye perylene orange, which has recently been shown to operate with very high efficiency in a porous glass host.

Optimized fabrication and laser performance of copolymer solid-state dye lasers

We report pulsed laser operation of rhodamine 530 dye in conventional MPMMA, and in a range of P(HEMA:MMA) copolymer hosts comprising methyl-methacrylate and 2-hydroxyethyl-methacrylate monomers. Samples of high optical quality have been fabricated.