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/cm<SUP>2</SUP>. 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/cm<SUP>2</SUP>. 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.
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.
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 Medlite<SUP>TM</SUP> 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$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/cm<SUP>2</SUP> has been achieved.
Experimental results for various type polymer lasers, pumped by different frequency doubled Nd:YAG lasers with pulse energy from 1 to 400 mJ, pulse width from 5 to 500 ns, and pulse repetition rate from 1 to 25,000 Hz, are presented. A dye laser output energy exceeding 280 mJ and an average output power of more than 12 W were demonstrated in a broad band operation mode. A total energy of 190 mJ at 560 nm in a beam divergence of less than 20 mm-mrad is achieved. A tunability over 545-685 nm wavelength range was demonstrated in a narrow band operation mode (linewidth 0.4 cm<SUP>-1</SUP>) with more than 30 mJ maximum energy per pulse. A stable output for more than 1 million pulses at 560 nm for motionless modified polymer element at pump fluence 0.5 J/cm<SUP>2</SUP> and more than 200 million pulses for movable element at pump fluence 1 J/cm<SUP>2</SUP> has been achieved.
The world's first high efficient quasi-CW polymer dye laser is described. An average output power of more than 6 W was achieved in a broad band operation mode, at 25 kHz pulse repetition frequency. A tunability over 555-660 nm wavelength range was demonstrated in a narrow band operation mode with minimum 0.5 W of average output power. A stable operation of the polymer laser for more than 2 hours was observed at output power level of 4 W. The integrated output energy of 30 kJ was obtained from one polymer element that corresponds o 220 million pulses.
The Q-switched Nd:YAG laser is the most recent in a series of pulsed laser systems for plastic surgery. The 532 nm wavelength has been shown to be absorbed by a variety of chromophores. These include tattoo pigments, oxygenated hemoglobin and melanin-containing epidermal cells. A simple multi-line solid state laser module pumped by double-frequency Q- switched YAG laser is presented. This solid state multi-line module enables tuning of the wavelength in the yellow spectral range to 560 nm or to 580 nm for dermatology applications. Conversion efficiency in excess of 70% was achieved at 10 Hz pulse repetition frequency and output energy per pulse of approximately 200 mJ.
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.
Fundamental aspects of multishot laser damage are considered: thermal instability in an optical medium due to pulseto--pulse accumulation o absorbing derects mechanisms o laser induced detect generation. Eeotive methods or suppressing a deeot rormation to increase laser damage resistance are discussed and illustrated by experimental data or various type optical materials. Key words: multishot and singleshot laser damage instability inclusion accumulation eect 5 thermochemical mechanochemicalprocesses thermoelastic stresses leser damage resistance of crystals and polymers laser conditioning. 1 .