Gennady A. Matyushin

Photostability of dye-doped modified polymers at extremely high intensities: Medlite laser systems

Presented here are experimental results for a high-energy solid-state dye laser with different laser resistant polymer active elements impregnated with pyrromethene and xanthene dyes. It was pumped by a unique frequency doubled MedliteTM IV Nd:YAG laser with pulse energies up to 660 mJ, pulse width 5 - 7 ns and pulse repetition rates up to 10 Hz developed by Continuum Biomedical. A dye laser output energy greater than or equal to 525 mJ in broad band operation mode and slope efficiency over 80% were demonstrated at pump fluences up to 3 J/cm

Polymer dye lasers with exceptional performance

2). No laser-induced damage of the modified polymer elements was detected up to these levels of fluence. A stable output for more than 150,000 pulses at 585 nm, for a fixed area of the polymer element, at a pump fluence of 1.3 J/cm2 has been achieved.

Modified polymers--effective host materials for solid state dye lasers and laser beam control elements: a review

Presented here are experimental results of polymer dye lasers with various active elements that had different optical surface quality. We investigated these active elements with diamond-turned and conventionally polished surfaces, uncoated and AR coated. Sol gel AR coatings were spin-applied to polymer surfaces resulting in less than 0.25%/surface reflection losses. Excellent refractive index matching coupled with low stress and high optical damage threshold, makes this AR coating ideal for this applications. Sol gel coatings are highly repeatable and easily tailored to these polymer materials. These elements were pumped by a Q-switched, frequency doubled Nd:YAG laser with pulse energies up to 760 mJ, pulsed width of 5 - 7 ns.

Efficient polymer dye lasers with variable wavelengths for medical applications

In many respects solid polymers are attractive hosts for dyes to produce on their base various optical elements for laser applications including tunable lasers and laser beam control saturable filters. For this reason various dye-impregnated polymer materials were extensively studied in many laboratories during last 25 years. A critical review of these studies is presented in this paper with main attention to analysis of processes responsible for major laser characteristics of dye - impregnated polymer materials: lasing efficiency, bleaching efficiency, laser damage resistance of polymer matrix, photostability of dyes under high power laser radiation and dye deterioration during long-term use and storage. Results achieved in General Physics Institute of Russian Academy of Sciences and collaborating industrial research laboratories on creation of highly effective dye-impregnated modified polymer materials for visible and near IR laser application possesing high laser damage resistance, dye photostability, laser oscillation efficiency and laser induced bleaching efficiency are presented. Limitations for polymer-host dye lasers, due to rather low thermal conductivity of polymer materials, arising, in particular, at flash la~p pumping and high repetition rates, are discussed. Some practical methods allowing to overcome these limitations are also discussed.

Transparent polymers: a new class of optical materials for lasers

Presented here are experimental results for a new high- energy/intensity polymer dye laser, with different laser resistant modified polymer elements impregnated with pyrromethene dyes. These polymers manufactured in Russia. They were pumped by a frequency doubled Medlite IV Nd:YAG laser developed by Continuum Biomedical with pulse energies up to 560mJ, pulse width 5 to 7ns with a beam sizes of 6mm and intensities up to 400MW/cm2. A maximum dye laser output energy up to 450mJ at 585nm and up to 310mJ at 650mm were achieved in broadband operation mode. Overall efficiency > 80% at 585nm and > 50% at 650 nm were obtained at pump fluences up to 2J/cm2. Variable wavelengths of 560 and 585nm in the yellow spectral range and 630 and 650nm in the red spectral range were demonstrated by choosing the proper polymer element with different laser dyes and a specially designed dichroic high reflector. A stable output of 250mJ for more than 50,000 pulses at 585nm and 150mJ for more than 20,000 pulses at 650nm has been achieved with the Multiple Dye Laser Handpiece developed by Continuum Biomedical. This was achieved with pump energies up to 400 mJ.