Высокомощный лазер на кристалле Yb3+:YAlO3, работающий в режиме синхронизации мод на основе полупроводниковых зеркал с насыщающимся поглотителем

Yttrium aluminium perovskite YAlO3 (YAP) crystal, doped with rare-earth ions, has been extensively studied as a diode-pumped laser host material. The wide interest to rare-earth ions doped YAP crystals is explained by its good thermal and mechanical properties, high natural birefringence, widely used Czochralski growth method. The aim of this work was to study the Yb3+:YAlO3 crystal as an active medium for high power mode-locked laser. Yb3+-doped perovskite-like aluminate crystals have unique spectroscopic and thermooptical properties that allowed using these crystals as an active medium of high power continuous wave (CW) and modelocked (ML) bulk lasers with diode pumping. In our work spectroscopic properties of Yb:YAP crystal and laser characteristics in CW and ML regimes are investigated. Maximum output power of 4 W with optical-to-optical efficiency of 16.3 % and 140 fs pulse duration have been obtained for Yb:YAP E //c-polarization with 10 % output coupler transmittance. Tunability range as wide as 67 nm confirms high promise of using Yb:YAP crystal for lasers working in wide spectral range

Регенеративный усилитель чирпированных импульсов на кристалле Yb3+:LuAlO3 с усилением отдельных спектральных компонент для применений в терагерцовой области спектра

Compact diode-pumped chirped pulse regenerative amplifier systems with pulse repetition rate of hundreds kilohertz based on Yb3+-doped crystals are of practical importance for wide range of applications such as materials processing, medicine, scientific research, etc. The aim of this work was to study the Yb3+:LuAlO3 crystal based dual wavelength chirped pulse regenerative amplifier. Perovskite-like aluminate crystals have unique spectroscopic properties that allowed to use amplifier active element gain spectrum as an amplitude filter for amplified pulse spectrum and even obtained dual wavelength amplification without any additional components. In our work a simple way to obtain dual-wavelength operation of chirped pulse regenerative amplifier by using the active medium gain spectrum as an amplitude filter for the formation of the amplified pulses spectrum demonstrated for the first time to our knowledge. Maximum output power of 5.4 W of chirped pulses (3.8 W after compression) and optical-to-optical efficiency of 22.5 % have been obtained for Yb:LuAP E//b-polarization at 200 kHz repetition rate. Compressed amplified pulse duration was about 708 fs while separate spectral components durations were 643 fs and 536 fs at 1018.3 nm and 1041.1 nm central wavelengths, respectively. Performed investigations show high potential of Yb3+:LuAP crystals as active elements of compact diode pumped chirped pulse regenerative amplifiers

Thermo-optic characterization of Yb:CaGdAlO4 laser crystal

Principal thermo-optic coefficients (TOCs), dno/dT and dne/dT, are measured for Yb:CaGdAlO4 crystal, for the first time, to our knowledge. At the wavelength of ~1 μm, they equal –7.6 and –8.6 (Ч10-6 K-1), accordingly. Thermal coefficients of the optical path (TCOP) are determined for this crystal for the principal crystal cuts (a-cut and c-cut) and light polarizations (π or σ). Thermo-optic dispersion formulas are evaluated for both TOC and TCOP coefficients. Optical power of thermal lens is measured for diode-pumped a-cut Yb:CaGdAlO4; it is also calculated on the basis of measured material parameters. Thermal conductivity of CaGdAlO4 crystal is measured versus Yb concentration. The results indicate that a-cut Yb:CaGdAlO4 can provide really "athermal" behavior

Компактный лазер на кристалле Yb3+:LuAlO3 с активной модуляцией добротности резонатора, излучающий на длине волны 999,6 нм для применения в лазерно-искровой эмиссионной спектроскопии

Compact actively Q-switched diode-pumped lasers based on Yb3+-materials are of practical importance for wide range of scientific, industrial and biomedical applications. The aim of this work was to study the Yb3+:LuAlO3 actively Q-switched laser.One of the most promising crystalline hosts for rare-earth ions are Perovskite-like aluminate crystals. Yttrium aluminate crystal YAlO3 (YAP) is a well-known host with good thermal and mechanical properties (thermal conductivity for undoped crystal is about 11 W/m·K and about 8 W/m·K for Yb(5 at.%):YAP) similar to those of YAG. The reduction in the thermal conductivity of doped laser crystal in comparison with host materials is small in the case of ions with close atomic mass and ionic radii such as for Yb3+ and Lu3+. This feature makes LuAlO3 (LuAP) more promising host crystal for doping by Yb3+ ions in contrast to YAP especially for high output power laser systems. In our work, for the first time to the best of our knowledge actively Q-switching laser operation of Yb3+:LuAP single crystal was demonstrated. The maximum average output power of 4.9 W at 50 kHz pulse repetition frequency (PRF) with opt.-to-opt. efficiency of 21 % was obtained with 30 % OC transmittance. Output power as high as 3.3 W with 333 µJ-laser pulses with duration of about 11.5 ns was demonstrated at 10 kHz PRF the corresponding pulse peak power was 29 kW. 97 µJ second harmonic pulses obtained with 29 % conversion efficiency at 10 kHz PRF.Performed investigations show high potential of Yb3+:LuAP crystals as active elements of compact diode pumped actively Q-switched lasers due to high stimulated emission cross-section (≈ 3.74·10-20 cm2) at 999.6 nm wavelength and significant reduction of heat load on the active element when pumping around 980 nm and generation around 999 nm.Компактные лазеры с активной модуляцией добротности резонатора, построенные на материалах, легированных ионами Yb3+, представляют практический интерес для широкого ряда научных, промышленных и биомедицинских применений. Целью данной работы являлось исследование режима активной модуляции добротности резонатора лазера на кристалле Yb3+:LuAlO3.Одними из наиболее перспективных матриц для легирования ионами редкоземельных элементов являются кристаллы алюминатов со структурой перовскита. Кристаллы иттриевого алюмината YAlO3 (YAP) широко известны в качестве матриц благодаря хорошим термомеханическим свойствам (теплопроводность нелегированного кристалла около 11 Вт/м·К и около 8 Вт/м·К для Yb(5 ат.%):YAP), близким к кристаллам YAG. Снижение теплопроводности лазерного кристалла при легировании по сравнению с чистой матрицей мало в случае незначительно отличающихся атомных масс и ионных радиусов как в случае с ионами Yb3+ и Lu3+. Данная особенность делает кристалл LuAlO3 (LuAP) значительно более перспективной матрицей для ионов Yb3+ по сравнению с YAP особенно в случае лазерных систем с высокой средней выходной мощностью.Режим активной модуляции добротности лазера на кристалле Yb3+:LuAP исследован впервые в нашей работе. Максимальная средняя выходная мощность 4,9 Вт получена при частоте следования импульсов 50 кГц и оптической эффективности 21 % с применением выходного зеркала пропусканием 30 %. Выходная мощность 3,3 Вт, длительность импульса 11,5 нс получены при частоте следования импульсов 10 кГц, энергия импульса составила 333 мкДж, пиковая мощность 29 кВт. Импульсы энергией 97 мкДж при частоте следования 10 кГц получены на частоте второй гармоники с эффективностью преобразования 29 %. Проведенные исследования показывают, что благодаря высокому поперечному сечению стимулированного излучения (≈ 3,74·10-20 см2 ) на длине волны 999,6 нм, а также существенному снижению тепловой нагрузку на активный элемент при накачке в области 980 нм и генерации в области 999 нм, кристаллы Yb3+:LuAP весьма перспективны в качестве активных элементов компактных твердотельных лазеров с диодной накачкой, работающих в режиме активной модуляции добротности. отельных лазеров с диодной накачкой, работающих в режиме активной модуляции добротности

Высокомощный лазер на кристалле Yb3+:YAlO3 ,работающий в режиме синхронизации мод на основе полупроводниковых зеркал с насыщающимся поглотителем

Yttrium aluminium perovskite YAlO3 (YAP) crystal, doped with rare-earth ions, has been extensively studied as a diode-pumped laser host material. The wide interest to rare-earth ions doped YAP crystals is explained by its good thermal and mechanical properties, high natural birefringence, widely used Czochralski  growth method. The aim of this work was to study the Yb3+:YAlO3  crystal as an active medium for high  power mode-locked laser.Yb3+-doped perovskite-like aluminate crystals have unique spectroscopic and thermooptical properties that allowed using these crystals as an active medium of high power continuous wave (CW) and modelocked (ML) bulk lasers with diode pumping.growth method. The aim of this work was to study the Yb3+:YAlO3  crystal as an active medium for high  power mode-locked laser.In our work spectroscopic properties of Yb:YAP crystal and laser characteristics in CW and ML regimes are investigated. Maximum output power of 4 W with optical-to-optical efficiency of 16.3 % and 140 fs pulse duration have been obtained for Yb:YAP E //c-polarization with 10 % output coupler transmittance. Tunability range as wide as 67 nm confirms high promise of using Yb:YAP crystal for lasers working in wide spectral range. Кристаллы иттрий-алюминиевого перовскита YAlO3 (YAP), легированные ионами редкоземельных элементов интенсивно изучались в качестве активных сред лазеров с диодной накачкой. Интерес к данным кристаллам обусловлен их высокими теплофизическими и механическими свойствами, высоким двулучепреломлением, возможностью роста по широко распространённому методу Чохральского. Целью данной работы было изучение кристалла Yb3+:YAlO3  в качестве активной среды лазера  с высокой средней выходной мощностью, работающего в режиме синхронизации мод.Кристаллы YAlO3, легированные трёхвалентными ионами иттербия имеют уникальные спектроскопические и теплофизические свойства, что позволяет использовать данные кристаллы в качестве активных сред лазеров с высокой средней выходной мощностью и диодной накачкой, работающих в режимах непрерывной генерации и пассивной синхронизации мод.В работе исследованы спектроскопические характеристики кристалла Yb:YAP, а также выходные характеристики лазеров на основе данного кристалла, работающих в режимах непрерывной генерации и пассивной синхронизации мод. Средняя выходная мощность 4 Вт с оптической эффективностью 16.3 % и длительностью импульса 140 фс получена для E//c-поляризации при пропускании выходного зеркала 10 %. Диапазон перестройки 67 нм подтверждает высокие перспективы использования кристалла Yb:YAP в качестве активной среды лазеров, работающих в широком спектральном диапазоне

Radiation-balanced lasing and amplification

Quantum statistical theory of radiation-balanced laser is constructed within method of nonequilibrium statistical operator. System of equations is derived for number of phonons and collective population difference. Their numerical solutions are obtained and discussed

Diode-pumped continuous Wave Tm:KLu(WO<inf>4</inf>)<inf>2</inf> and Tm:KY(WO<inf>4</inf>)<inf>2</inf> microchip lasers

© 2016 IEEE.Laser performance of Tm doped KLu(WO4)2 and KY(WO4)2 crystals was investigated in a microchip cavity configuration with fiber coupled laser diode as a pump source. The highest output power of 1013 mW with 51 % slope efficiency was obtained for Tm:KY(WO4)2 crystal. Using Tm:KLu(WO4)2 crystal output power of 912 mW and slope efficiency of 38 % were achieved

Energy transfer in Tm,Ho:KYW crystal and diode-pumped microchip laser operation

© 2016 Optical Society of America.An investigation of Tm-Ho energy transfer in Tm(5at.%),Ho(0.4at.%):KYW single crystal by two independent techiques was performed. Based on fluorescence dynamics measurements, energy transfer parameters P71 and P28 for direct (Tm→Ho) and back (Ho→Tm) transfers, respectively, as well as equilibrium constant Θ were evaluated. The obtained results were supported by calculation of microscopic interaction parameters according to the Förster-Dexter theory for a dipoledipole interaction. Diode-pumped continuous-wave operation of Tm,Ho:KYW microchip laser was demonstrated, for the first time to our knowledge. Maximum output power of 77 mW at 2070 nm was achieved at the fundamental TEM00 mode

Energy transfer in Tm,Ho:KYW crystal and diode-pumped microchip laser operation

© 2016 Optical Society of America.An investigation of Tm-Ho energy transfer in Tm(5at.%),Ho(0.4at.%):KYW single crystal by two independent techiques was performed. Based on fluorescence dynamics measurements, energy transfer parameters P71 and P28 for direct (Tm→Ho) and back (Ho→Tm) transfers, respectively, as well as equilibrium constant Θ were evaluated. The obtained results were supported by calculation of microscopic interaction parameters according to the Förster-Dexter theory for a dipoledipole interaction. Diode-pumped continuous-wave operation of Tm,Ho:KYW microchip laser was demonstrated, for the first time to our knowledge. Maximum output power of 77 mW at 2070 nm was achieved at the fundamental TEM00 mode

In-band pumped room-temperature Er:KY(WO4)2 laser emitting around 1:6 mm

We present efficient continuous-wave operation of an Er:KY(WO 4)2 crystal under in-band pumping by a compact diode-pumped Er, Yb:GdAl3(BO3)4 laser. Maximum slope efficiency of 27% and output power of 35 mW at 1609.5 nm were obtained with beam propagation factor M2 < 1:2. Absorption and stimulated emission cross-section spectra, as well as the radiative lifetime of the 4I13=2 energy level, were determined