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1.
We demonstrate the acquisition of high-quality two-photon fluorescence microscopy images using an all-solid-state self-mode-locked Cr:LiSAF laser. We contrast the performance of the two-photon technique with single-photon confocal fluorescence microscopy images taken with an argon-ion laser. Examples of improved depth penetration and reduced dye bleaching are presented.  相似文献   

2.
Many kinds of experiments about all solid-state Cr:LiSAF lasers have been reported. A tunable all solid-state cw laser having tunability over more than 100 nm was developed by using the spectrum selection self-injection locking (SSSIL) method in 1992. The authors realize tunable picosecond radiation from an all solid-state laser with 146-200 ps pulses in an 88 nm range. Also, 70 fs pulse generation was achieved using a Kerr-lens mode-locking pumped with an Ar+ laser  相似文献   

3.
Peng X  Xu L  Asundi A 《Applied optics》2005,44(5):800-807
We describe experimental results with a diode-pumped, intracavity-doubled cw Nd:YLF laser in multilongitudinal mode and TEM00 spatial transverse mode with a critical phase-matched lithium triborate crystal. Taking into account the thermal effects of Nd:YLF, energy-transfer upconversion, and the thermal fracture limit, we set up a power-scaling model to optimize and design a fundamental diode-pumped Nd:YLF laser. A highly efficient second-harmonic laser was achieved, based on the optimized cavity design. A second-harmonic-generation output power of 20.5 W at a wavelength of 527 nm was obtained at an incident pump power of 60 W, corresponding to an optical-to-optical efficiency of 34.2%. The TEM00 mode green laser operates at a measured M2 parameter of 1.2. The instability of the green laser power is less than +/- 1% RMS.  相似文献   

4.
An ultrafast, hybrid mode-locked semiconductor laser-diode system has been used to seed a flash-lamp-pumped Cr:LiSAF regenerative amplifier system, producing subpicosecond pulses with millijoule output pulse energy. This system has the potential to eliminate argon-ion-pumped-based, ultrafast laser systems.  相似文献   

5.
We report the measurement of the 20 ps ablation threshold of pure and Cr(3+) doped LiSAF samples using a simple method that employs a single scan of the sample across a focused laser beam waist. During the scan, a profile is etched in the sample surface, and the measurement of the maximum transversal size of the profile and the pulse peak power determine the ablation threshold, without any further knowledge of the beam geometry. Also, it was possible to measure the depth of the ablation profile, to calculate its effective volume, and to identify that the maximum material removal rate per pulse does not occur at the beam waist, which is not intuitively expected.  相似文献   

6.
氟化物激光晶体Cr:LiSAF的坩埚下降法生长   总被引:2,自引:0,他引:2  
陈红兵  徐家跃  夏海平  范世 《功能材料》2002,33(4):442-443,446
报道了氟化物激光晶体CrLiSAF的坩埚下降法生长工艺.采用经氟化处理的无水氟化物原料,按照LiFSrF2(AlF3+CrF3)=111的摩尔比配料,控制炉体温度于900~940℃,晶体生长速度为0.4~0.8mm/h,通过密闭条件下的坩埚下降法生长出大尺寸(φ25mm×85mm)的优质完整的CrLiSAF单晶.  相似文献   

7.
A model is presented of pulse evolution in broadband intra-cavity frequency-doubled lasers. The model utilizes normalized coupled rate equations for each mode, including terms that represent the loss due to nonlinear mixing between longitudinal modes. The pulse energy, shape, peak power and duration are calculated by numerical solution of these equations. The model shows that the pulse duration depends not only on the initial population inversion, photon lifetime and the effective nonlinear coupling coefficient, as is the case for narrowband lasers, but also on the fundamental bandwidth. A gain-switched Ti:sapphire laser, pumped by a Q-switched Nd-doped yttrium aluminium garnet laser at 532?nm, was frequency doubled using an intra-cavity β-barium borate crystal. The bandwidth was reduced from about 25?nm to about 1.5?nm in two steps using a series of prisms, and the resulting changes in experimental pulse durations and energies agree well with the model.  相似文献   

8.
A prototype solid-state, multispectral hybrid laser has been designed and tested. The laser provides simultaneous outputs at several wavelengths. The hybrid-laser concept is based on the efficient use of flash-lamp-pump energy distributed between two complementary lasing materials, Nd:YAG and Cr:LiSAF, that share the same pump cavity. The prototype Q-switched hybrid laser provides dual-fundamental-wavelength output at 850 and 1064 nm as well as frequency-doubled output at 532 nm. The laser achieved 3.6% slope efficiency (combined) in free-running operation and 2.4% when Q switched. Higher efficiencies can be obtained with improvements in laser crystal quality and pump cavity configuration.  相似文献   

9.
Pinto JF  Esterowitz L 《Applied optics》1998,37(15):3272-3275
The performance of a flash-lamp-pumped Cr:LiSAF unstable laser resonator utilizing a fourth-order super-Gaussian variable reflectivity mirror as an output coupler is described. The super-Gaussian mirror results in a smooth, flattop transverse beam profile in the near field that is advantageous for nonlinear frequency-conversion applications. Long-pulse and Q-switched operation of the Cr:LiSAF unstable laser resonator are described and compared with stable resonator operation. We obtained tunable ultraviolet radiation extending from 267 to 290 nm by frequency mixing theQ-switched Cr:LiSAF laser output with lithium triborate and beta-barium borate nonlinear crystals.  相似文献   

10.
Cr3+:LiSrAlF6 crystals are an interesting laser medium because of their spectroscopic characteristics: They present a broad emission band in the near infrared and can be pumped either by a flashlamp or by diodes. Up to now, their limitation has been mostly due to their poor thermal properties that limit the laser performance either in the repetition rate in a pulsed system or output power in cw systems. We have designed and constructed a flashlamp-pumped laser using a standard rod pumping cavity that avoids most of the heat generated in the pumping process and allows operation at a fairly high repetition rate of 30 Hz with a high average power of 20 W in a conservative operation mode.  相似文献   

11.
An innovative pump concept for diode-pumped, solid-state lasers is introduced as an example for an Er:YSGG laser, permitting its miniaturization. Embedded in a multireflective pump cavity, the laser crystal is simultaneously side and end pumped. Specially calculated and shaped deflecting optics distribute the coaxially input pumping light homogeneously over the lateral surface of the crystal, therefore reducing the size of the laser head, including the optical resonator, to a length of 27.5 mm and an outside diameter of 12.5 mm. The differential efficiency achieved is between 8.7% and 24%. The laser emits energy of 15.7 mJ at an absolute efficiency of 9.1% and a repetition rate of 4 Hz.  相似文献   

12.
Ng SP  Tang DY  Qin LJ  Meng XL  Xiong ZJ 《Applied optics》2006,45(26):6792-6797
By using the natural birefringence of an a-cut Nd:GdVO(4) crystal, we experimentally investigate laser operation under different light polarizations (pi- and sigma-polarized emissions) and compare their performance. The laser performance is further compared with a diode-pumped c-cut Nd:GdVO(4) laser of the same parameters. We show experimentally that the c-cut Nd:GdVO(4) laser could have good passively Q-switched performance in a low-pump-power region but is influenced by other intrinsic laser effects, such as the thermally induced cavity losses; its performance is severely degraded under high pump power. The best passively Q-switched performance obtained in our experiments is from the a-cut pi-polarized laser, which gives the narrowest pulse of 5.4 ns with the highest peak power of 20 kW. Our experimental results show that, to achieve the best performance of the passively Q-switched laser operation, an overall consideration of laser parameters is important.  相似文献   

13.
Bartnicki E  Bourdet GL  Ynard M 《Applied optics》2007,46(29):7190-7195
We present a new apparatus making possible both homogeneity and multipass pumping. It is made up of a square section kaleidoscope made of transparent medium on the terminal faces of which are set mirrors with transparent holes at the centers. The kaleidoscope homogenizes the beam. The pump power reflected by the amplifier medium returns in the kaleidoscope, and the mirrors reflect this pump light toward the amplifier medium.  相似文献   

14.
Kasamatsu T  Sekita H  Kuwano Y 《Applied optics》1999,38(24):5149-5153
We have investigated the temperature dependence of output performances for 970-nm diode-pumped Yb:YAG (Yb(3+):Y(3)Al(5)O(12)) and Yb:LuAG (Yb(3+):Lu(3)Al(5)O(12)) lasers over the wide temperature range from 80 to 310 K. Temperature-optimized operation was experimentally demonstrated at around 160 K and was theoretically confirmed by taking into account the absorption spectra change of Yb crystals at low temperatures. Cooling the crystal to below 160 K caused a narrowing of the absorption bandwidth and led to a decrease in output power and efficiency.  相似文献   

15.
《Optical Materials》2010,32(12):1888-1890
Single crystals of CdSe:Cr and CdS:Cr with the doping level up to 1019 cm−3 were grown by a vapor phase contact-free technique. An efficient room-temperature pulsed and continuous wave (CW) lasing with the CdSe:Cr crystal was achieved. First a pulsed lasing with the CdS:Cr crystal was also demonstrated. The slope efficiency on the absorbed energy was as high as 46.5% for Cr2+:CdSe and 39% for Cr2+:CdS lasers. Using an intra-cavity prism, the Cr2+:CdSe laser wavelength was continuously tuned from 2.26 to 3.61 μm while the Cr2+:CdS laser from 2.2 to 3.3 μm. For the laser wavelength, the crystal passive loss coefficient was estimated to be smaller than 0.045 cm−1 for CdSe:Cr crystals and 0.039 cm−1 for CdS:Cr crystals. For the Cr2+:CdSe laser, the CW output power up to 1.07 W was achieved.  相似文献   

16.
Single crystals of CdSe:Cr and CdS:Cr with the doping level up to 1019 cm−3 were grown by a vapor phase contact-free technique. An efficient room-temperature pulsed and continuous wave (CW) lasing with the CdSe:Cr crystal was achieved. First a pulsed lasing with the CdS:Cr crystal was also demonstrated. The slope efficiency on the absorbed energy was as high as 46.5% for Cr2+:CdSe and 39% for Cr2+:CdS lasers. Using an intra-cavity prism, the Cr2+:CdSe laser wavelength was continuously tuned from 2.26 to 3.61 μm while the Cr2+:CdS laser from 2.2 to 3.3 μm. For the laser wavelength, the crystal passive loss coefficient was estimated to be smaller than 0.045 cm−1 for CdSe:Cr crystals and 0.039 cm−1 for CdS:Cr crystals. For the Cr2+:CdSe laser, the CW output power up to 1.07 W was achieved.  相似文献   

17.
Single-longitudinal-mode operation of gain-switched Cr4+ laser, with output energy as much as 1.9 mJ, is reported from two different coupled-cavity resonators. A prism-coupled cavity and a modified Michelson interferometric grazing-incidence (MIGI) cavity was pumped by a multilongitudinal-mode Q-switched Nd:YAG laser; the modified MIGI cavity obtained 100-MHz-bandwidth laser output tunable between 1150 and 1330 nm. Conversion efficiency of 3.2% (slope efficiency of 4%) was achieved, with a pump threshold density as small as 0.2 J/cm2. Mode spacing of the laser output in multilongitudinal mode showed increased mode spacing in agreement with a coupled-cavity theory.  相似文献   

18.
Jackson SD  Piper JA 《Applied optics》1995,34(12):2012-2023
We have developed a thermal model for the determination of the temperature distribution of a diode side-pumped Nd:YAG laser in which the laser rod is fixed in a solid nonfocusing (prismatic) pump-light collector. The model permits the temperature to be determined as a function of both spatial and temporal parameters for a wide range of boundary conditions and different collector materials. Interferometric measurements were carried out to obtain the averaged rod temperatures for comparison with results from the model and to fix a convective-cooling rate for ambient air that best fits the experimental results. Two cases were studied both theoretically and experimentally with artificial sapphire and BK7 as prism materials, and good agreement was achieved between model and experimental results. The use of artificial sapphire as the prism material reduces by a factor of ~7 both the rod temperature and the warm-up time compared with BK7 glass. Peltier cooling of the underside of the BK7 glass prism yields thermal Characteristics of the device that are similar to those devices with sapphire prisms. Calculations also show that the thermal properties of the fixant are not critical for moderate fixant thermal diffusivities (i.e., k(f) > 10(-8)-10(-7) m(2) s(-1)), thus the choice of an appropriate fixant can be based on its mechanical and index-matching properties alone.  相似文献   

19.
We demonstrate and investigate a peculiar mode of cw Yb3+-doped crystal laser operation when two emissions, at two independently tunable wavelengths, are simultaneously produced. Both emissions are generated from a single pumped volume and take place in either a single beam or spatially separated beams. The laser employs original two-channel cavities that use a passive self-injection-locking (PSIL) control to reduce intracavity loss. The advantages of the application of the PSIL technique and some limitations are shown. The conditions for two-wavelength multimode operation of the cw quasi-three-level diode-pumped Yb3+ lasers and the peculiarity of such an operation are carried out both theoretically and experimentally. The results reported are based on the example of a Yb3+:GGG laser but similar results are also obtained with a Yb3+:YAG laser. The laser operates in the 1023-1033-nm (1030-1040-nm) range with a total output power of 0.4 W. A two-wavelength, single longitudinal mode generation is also obtained.  相似文献   

20.
The FM spectroscopy technique has been applied to two frequency-doubled Nd:YAG lasers to achieve absolute frequency stabilization against the hyperfine structure components of the rovibronic P(54) 32-0 iodine line at 532 nm. A fractional frequency stability of 2 x 10(-13) tau(-1/2) has been obtained for integration times in the range of 1 ms < tau < 10 s. For longer integration times the stability level remains below 10(-13), reaching a minimum value of 4.6 x 10(-14) at 100 s. This high stability level is, to our knowledge, the best value achieved against iodine lines by this locking method and for a fully transportable system.  相似文献   

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