Showing papers in "Laser Physics Letters in 2008"
TL;DR: A brief review of laser-based generation methods is presented, starting from the schemes of resonance laser excitation of photoconductive materials, organic molecules and ionized gases, and proceeding with more detailed description of non-resonance schemes of optical rectification and difference frequency generation in materials with high optical nonlinearity as discussed by the authors.
Abstract: Generation of high-power radiation in terahertz frequency range 0.3 – 10 THz is a fast developing research area attracting considerable interest over the past years due to its important applications in spectroscopy, communication, biomedical imaging and tomography. A brief review of laser-based generation methods is presented, starting from the schemes of resonance laser excitation of photoconductive materials, organic molecules and ionized gases, and proceeding with more detailed description of non-resonance schemes of optical rectification and difference frequency generation in materials with high optical nonlinearity. Recent progress achieved in both groups of methods is compared.
176 citations
TL;DR: In this paper, the main effects in and around gold nanoparticles under action of short (nano-, pico-, and femtosecond) laser pulses with focus on photoacoustic effects due to the thermal expansion of nanoparticles and liquid around them.
Abstract: In medical applications of laser and nanotechnology to diagnosis and treat cancer or microorganisms, understanding of lased-induced photothermal (PT) and accompanied phenomena around nanoparticles are crucial for optimization and bringing this promising technology to bedside. We analyzed the main PT-based effects in and around gold nanoparticles under action of short (nano-, pico-, and femtosecond) laser pulses with focus on photoacoustic effects due to the thermal expansion of nanoparticles and liquid around them, thermal protein denaturation, explosive liquid vaporization, melting and evaporation of nanoparticle, optical breakdown initiated by nanoparticles and accompanied to shock waves and explosion (fragmentation) of gold nanoparticles. Characteristic parameters for these processes such as the temperature and pressures levels, and laser intensity thresholds among others are summarized to provide basis for comparison of different mechanisms of selective nanophotothermolysis and diagnostics of different targets (e.g., cancer cells, bacteria, viruses).
172 citations
TL;DR: In this article, a diode-pumped single frequency Tm:YAG laser operating at 2 μm is demonstrated, where two solid uncoated fused silica etalons are employed to narrow the laser line width, the thickness of which are 0.1 mm and 1 mm, respectively.
Abstract: A diode-pumped single frequency Tm:YAG laser operating at 2 μm is demonstrated in this letter. The laser crystal is controlled at room temperature by using a thermoelectric cooler. Two solid uncoated fused silica etalons are employed to narrow the laser line-width, the thicknesses of which are 0.1 mm and 1 mm, respectively. By tuning the angle of the etalons, single frequency laser is achieved and the oscillating wavelength can be changed from 2008 nm to 2021 nm. And at each wavelength, single-frequency laser is achieved. The maximum single frequency laser power is up to 75.0 mW with the central wavelength of 2013.9 nm. To our knowledge, this is the first time to obtain single-frequency Tm:YAG laser of 75.0 mW with F-P etalons in the cavity.
93 citations
TL;DR: In this article, the authors proposed a novel multi-wavelength erbium-doped fiber laser by using two polarization controllers and a sampled chirped fiber Bragg grating (SC-FBG).
Abstract: We have proposed a novel multi-wavelength erbium-doped fiber laser by using two polarization controllers and a sampled chirped fiber Bragg grating(SC-FBG). On the assistance of SC-FBG, the proposed fiber lasers with excellent stability and uniformity are tunable and switchable by adjusting the polarization controllers. Our laser can stably lase two waves and up to eight waves simultaneously at room temperature.
86 citations
TL;DR: In this article, the first pulsed deep-blue laser at 456 nm by acousto-optical Q-switching and intracavity frequency doubling of a diode-end-pumped Nd:GdVO4 laser was presented.
Abstract: We present what is, to the best of our knowledge, the first pulsed deep-blue laser at 456 nm by acousto-optical Q-switching and intracavity frequency doubling of a diode-end-pumped Nd:GdVO4 laser on the 4F3/2 → 4I9/2 transition at 912 nm. When the incident pump power is 36 W, the maximum single pulse energy of 44.1 μJ, pulse duration of 140 ns and peak power of 315 W are achieved at 10 kHz; the maximum average power of 770 mW, pulse duration of 200 ns and peak power of 193 W are obtained at 20 kHz. The fluctuation of the blue output power is less than 2.4% within the given 20 min at the maximum blue output power.
83 citations
TL;DR: It is found that embryonic imaging is improved by application of glycerol as optical clearing agent, and time-resolved profiles for OCT signal enhancement are presented.
Abstract: Optical coherence tomography (OCT) holds great promise as a routine research tool for 3-D analysis of mammalian embryos. However, despite the depth penetration afforded by this imaging modality, light attenuation in tissues imposes limitations. Here we studied the optical clearing effect of different concentrations of glycerol in mouse embryos. Depth- and time-resolved profiles for OCT signal enhancement are presented. We found that application of 50% glycerol resulted in 51.5±12.5% improvement of the OCT signal, while 25% glycerol enhanced the OCT signal by 25.2±7.3% at the depth of about 200 to 500 μm, and the glycerol permeability rate was estimated as 26.7±6 μm/min. These results demonstrate that embryonic imaging is improved by application of glycerol as optical clearing agent.
82 citations
TL;DR: In this paper, the authors focus on the use of magnetostrictive materials and the acousto-optic interaction to develop efficient Q-factor modulators for all-fiber laser cavities.
Abstract: Q-switching of fiber lasers using bulk elements has important drawbacks as reduced mechanical stability and high insertion losses. The development of efficient all-fiber modulation techniques is the key to obtain robust, compact and efficient Q-switched all-fiber lasers. Certainly, the development of fiber Bragg gratings (FBG) has been crucial to make progress on fiber lasers. FBGs permit a simple way to assemble all-fiber laser cavities and can be written in the active fiber itself. The Q-factor of this type of cavities is determined by the reflectivity of the FBGs and the losses of the fiber. Here, we focus on the use of magnetostrictive materials and the acousto-optic interaction to develop efficient Q-factor modulators. Most of these modulators include an FBG and take advantage of the specific interaction of the magnetostrictive materials or the acoustic wave with the FBG itself. Fiber optic technologies permit the development of a rather unique type of fiber lasers, i.e., actively Q-switched distributed feedback (DFB) fiber lasers. In this case, both the use of magnetostrictive materials and the acousto-optic interaction permit the generation of dynamic defects in an FBG that has been previously written in a highly Er-doped fiber.
79 citations
TL;DR: In this article, the photodegradation of three different chlorine photosensitizers (Photoditazine, Radachlorin, and Foscan®) was analyzed by changes in the fluorescence spectrum during illumination.
Abstract: In this paper, we report the photodegradation of three different chlorine photosensitizers (Photoditazine®, Radachlorin®, and Foscan®). The photosensitizer degradation was analyzed by changes in the fluorescence spectrum during illumination. The rate of fluorescence variation was normalized to the solution absorption and the photon energy resulting in the determination of the necessary number of photons to be absorbed to induce photosensitizer photodegradation. The parameter for rate of the molecules decay, the photon fluence rate and optical properties of the solution allow us to determine the photosensitizer stability in solution during illumination. The results show that the order of susceptibility for photodegradation rate is: Radachlorin® < Photoditazine® < Foscan®. This difference in the photodegradation rate for Foscan can be explained by the high proportion of aggregates in solution that inhibit the photo-oxidative process that impede the singlet oxygen formation. We hypothesize that there is a correlation between photodegradation rate and photodynamic efficacy witch is governed by the singlet oxygen formation responsible for the most relevant reaction of the cell death photodynamic induction. Then its is important to know the photostability of different types of drugs since the photodegradation rate, the photodegradation as well as the photodynamic efficacy are strong correlated to the oxygen concentration in the tissue.
74 citations
TL;DR: In this paper, a linear cavity Brillouin fiber laser (BFL) is proposed and demonstrated for multi-wavelength operation, which uses a single mode fiber (SMF) as a nonlinear gain medium.
Abstract: A linear cavity Brillouin fiber laser (BFL) is proposed and demonstrated for multi-wavelength operation. The BFL uses a single mode fiber (SMF) as a non-linear gain medium and an optical circulator to generate a linear cavity resonator. Two couplers are used to inject the Brillouin Pump (BP) and tap the BFL output respectively. The effect of the coupler ratio on the BFL performance is studied by keeping constant the ratio of the first coupler and varying the ratio of the second coupler. 11 simultaneous lines with a line spacing of 0.8 nm are obtained at a BP of 11.7 dBm and a coupler ratio of 95:5. The laser output is stable at room temperature with 5 lines obtained at above – 30 dBm, and has the largest signal to noise ratio observed at the remaining lines. The proposed BFL has the advantage of being able to operate at any wavelength and is only dependent on the available BP wavelength.
72 citations
TL;DR: In this article, a femtosecond Ti:Sapphire Q-switched and mode locked laser (Libra-S, Coherent, Palo Alto, CA, USA), emitting pulses with 70 fs width, radiation wavelength of 801 nm, at a constant pulse repetition rate of 1 KHz, was operated at different power levels with constant exposition time of 10 seconds, at focused and defocused mode.
Abstract: The study of the interaction of intense laser light with matter, as well as transient response of atoms and molecules is very appropriated because of the laser energy concentration in a femtosecond optical pulses. The fundamental problem to be solved is to find tools and techniques which allow us to observe and manipulate on a femtosecond time scale the photonics events on and into the matter. Six third human extracted molars were exposed to a femtosecond Ti:Sapphire Q-switched and mode locked laser (Libra-S, Coherent, Palo Alto, CA, USA), emitting pulses with 70 fs width, radiation wavelength of 801 nm, at a constant pulse repetition rate of 1 KHz. The laser was operated at different power levels (70 to 400 mW) with constant exposition time of 10 seconds, at focused and defocused mode. Enamel and dentin surfaces were evaluated concerned ablation rate and morphological aspects under scanning electron microscopic. The results in this present experiment suggest that at the focused mode and under higher average power, enamel tissues present microcavities with higher depth and very precise edges, but, while dentin shows a larger melt-flushing, lower depth and melting and solidification aspect. In conclusion, it is possible to choose hard or soft ablation, under lower and higher average power, respectively, revealing different aspects of dental enamel and dentin, depending on the average power, fluence and distance from the focal point of the ultra-short pulse laser on the tooth surface.
66 citations
TL;DR: In this paper, a regular and robust Q-switched and mode-locked (QML) pulses are produced in Nd:GdVO4 laser by the integration of nonlinear mirror and semiconductor saturable absorber mirror.
Abstract: Regular and robust Q-switched and mode-locked (QML) pulses are produced in Nd:GdVO4 laser by the integration of nonlinear mirror and semiconductor saturable absorber mirror. The threshold of QML operation is increased by putting the SESAM in laser cavity with large beam radius. The nonlinear mirror absorber can further increase nonlinear loss modulation of pulses to produce the stable and periodic QML pulses.
TL;DR: In this article, the dependences of pulse width, pulse repetition rate on incident pump power at different small-signal transmissions of Cr4+:YAG are measured for the green-light pulses.
Abstract: A laser-diode-pumped passively-Q-switched intracavity-frequency-doubled Nd:YVO4/YVO4 green laser with a MgO-PPLN and Cr4+:YAG is realized. The dependences of pulse width, pulse repetition rate on incident pump power at different small-signal transmissions of Cr4+:YAG are measured for the green-light pulses. The corresponding pulse energy and peak power are also been obtained.
TL;DR: In this article, the authors investigated the Tm:YLF laser output spectrum with an F-P etalon in the cavity, and acquired near-diffraction limited laser output.
Abstract: High power and high beam quality continuous wave Tm:YLF laser by the dual-end-pumped is presented in this letter. The highest output power reaches 21.3 W when the totally input pump power is 54.6 W. The optical conversion efficiency is 39.0% and the slope efficiency is 47.3%. With an F-P etalon in the cavity, the output center wavelength is tuned to 1908 nm with about 0.5 nm FWHM. With the optimal cavity, the beam quality factor M2 can be ~ 1.1. As we know, our work is the first time to investigate the Tm:YLF laser output spectrum with an F-P etalon in the cavity, and acquire near-diffraction limited laser output.
TL;DR: In this paper, high-order Raman-induced Stokes and anti-Stokes generation was observed in tetragonal YPO4 crystal and the discovered nonlinear-laser properties of this orthophosphate material significant increase the possibilities for its practical application.
Abstract: High-order Raman-induced Stokes and anti-Stokes generation was observed in tetragonal YPO4 crystal. The discovered nonlinear-laser properties of this orthophosphate material significant increase the possibilities for its practical application. The SRS-promoting modes derive both from stretching vibrations of the phosphate ion, and from combinations of these modes.
TL;DR: In this article, a tunable band-pass filter was used to produce tunable multi-wavelength Brillouin-erbium fiber laser within a Fabry-Perot cavity.
Abstract: The paper demonstrates the utilization of a tunable band-pass filter in producing tunable multi-wavelength Brillouin-erbium fiber lasers within a Fabry-Perot cavity. The optimization of the Brillouin pump wavelength position within the bandwidth of the self-lasing cavity modes is important to achieve the maximum stable output channels. The same number of 14 output channels with constant channel spacing of 10.5 GHz were able to be generated within 32 nm range. Besides the tunability, this design also has the advantage of consistent power requirement of both the 980 nm laser diode and the Brillouin pump in generating the 14 channels through the broad tuning range.
TL;DR: In this article, a compact high-power passively mode-locked Nd:LuVO4 laser by use of semiconductor saturable absorber mirror (SESAM) is presented.
Abstract: We report on a compact high-power passively mode-locked Nd:LuVO4 laser by use of semiconductor saturable absorber mirror (SESAM). The laser generated clean CW mode-locked pulses with an average output power of 8.6 W, a repetition rate of 144 MHz, and a pulse duration of 13.2 ps. By employing a three-mirror cavity scheme, the laser setup has only a footprint size of 70×30 cm2, which can be packaged to a portable laser system for convenient applications.
TL;DR: In this paper, a quad-wavelength fiber ring laser using a semiconductor optical amplifier (SOA) as gain medium and an array waveguide grating (AWG) as a selective wavelength filter is proposed and demonstrated.
Abstract: A quad-wavelength fiber ring laser using a semiconductor optical amplifier (SOA) as a gain medium and an array waveguide grating (AWG) as a selective wavelength filter is proposed and demonstrated. The quad-wavelength fiber ring laser is capable of generating four laser wavelengths at 1531.0 nm, 1533.3 nm, 1535.7 nm, and 1538.0 nm with a peak power at –20 dBm and a channel spacing of 0.24 nm (300 GHz) corresponding to the channel spacing of the selected AWG ports. The quad-wavelength ring laser shows stable operation over time with negligible fluctuations in the peak power of the lasing wavelengths. The separation of the two lasing wavelengths can be tuned over several nanometers by changing the ports of the AWG. The proposed laser configuration has the advantage of stable quad-wavelength output at room temperature as well as a simple and compact design with many potential DWDM and sensor applications.
TL;DR: In this paper, a new saturable absorber V3+:YAG, a flash-lamp-pumped passively Q-switched Nd:GdVO4 laser at 1.34 μm has been realized.
Abstract: By using a new saturable absorber V3+:YAG, a flash-lamp-pumped passively Q-switched Nd:GdVO4 laser at 1.34 μm has been realized. Both a-cut and c-cut Nd:GdVO4 crystals are used. The output single-pulse energy and the pulse width versus the pump energy for different initial transmissions of V3+:YAG saturable absorbers are measured. The experimental results show that, c-cut Nd:GdVO4 laser can generate the shorter pulse width and higher energy in comparison to a-cut one.
TL;DR: In this paper, a tunable multiwavelength erbium-doped fiber laser based on a polarization-maintaining photonic crystal fiber (PM-PCF) Sagnac loop filter is presented.
Abstract: We propose and demonstrate a tunable multiwavelength erbium-doped fiber laser based on a polarization-maintaining photonic crystal fiber (PM-PCF) Sagnac loop filter. Stable, room-temperature operation is obtained by employing a nonlinear optical loop mirror. At a central wavelength of 1563.000 nm, we generate 60 wavelengths within 3-dB bandwidth. The measured power fluctuation for each lasing wavelength is less than 0.2 dB in half an hour. Furthermore, by adjusting the polarization controllers in the Sagnac filter, wavelength locations of the laser lines with a fixed channel spacing of ~ 0.078 nm can be continuously shifted.
TL;DR: In this article, the continuous wave (CW) and passive Q-switching performance of a high-power diode-pumped Nd:GGG laser was reported, achieving a CW output power of 7.20 W under an absorbed pump power of 14.97 W, which gives a slop efficiency of 52.7%.
Abstract: We report on the continuous wave (CW) and passive Q-switching performance of a high-power diode-pumped Nd:GGG laser. A CW output power of 7.20 W was obtained under an absorbed pump power of 14.97 W, which gives a slop efficiency of 52.7%. With a Cr4+ doped yttrium aluminum garnet crystal as the saturable absorber, the shortest passively Q-switched pulse width, largest pulse energy, and highest peak power achieved were 7.7 ns, 126.25 μJ, and 15.5 kW, respectively.
TL;DR: Spectral Phase Interferometry for Direct Electric-field Reconstruction (SPIDER) as mentioned in this paper is a device that measures ultrashort pulses, utilizing spectral shearing interferometry and directly recovering the spectral phase.
Abstract: It was ten years ago in Rochester, New York that the first SPIDER was built. This simple acronym belies the subtleties of its inner workings; Spectral Phase Interferometry for Direct Electric-field Reconstruction (the ``f'' in field conveniently missed the cut) is a device that measures ultrashort pulses, utilizing spectral shearing interferometry and directly recovering the spectral phase. The very first SPIDER apparatus occupied nearly half an optical table, used a scanning monochromator, and had no computerized inversion routine. In the intervening decade, SPIDER has grown up. It has found a strong foothold in ultrafast laboratories throughout the world. Multiple groups have found useful new applications with this vital measurement tool, while others have contributed to the improvement of SPIDER itself, reaching to ever shorter pulses, new wavelength regimes, and making devices more sensitive, robust, smaller and faster. It also adapts to a field of research that changes rapidly. It was first designed to track and quantify the remaining spectral phase in a pulse to perfect its compression. In ten years, with the advent of pulse shapers, the real benefits of field diagnostics are becoming apparent. We have shifted away from the race towards the shortest IR pulse to a wide use of complex shaped pulses in almost every spectral range from far IR to XUV. But the quest of the shortest pulse is not over and new compression techniques utilize really broad spectra that are highly structured. All these applications provide new challenges for characterization techniques.
TL;DR: Melilite-type Ba2MgGe2O7 was found to be an attractive, simultaneously χ(2)- and χ (3)-active nonlinear optical crystal as mentioned in this paper.
Abstract: Melilite-type Ba2MgGe2O7 was found to be an attractive, simultaneously χ(2)- and χ(3)-active nonlinear optical crystal. Under one-micron picosecond pumping we observed several manifestations of nonlinear interactions, namely almost sesqui-octave Stokes and anti-Stokes lasing combs, collinear and ``Cherenkov''-type SHG, THG, SFG, and cascaded self-conversion χ(3) ↔ χ(2) generation in the visible and UV range. All recorded lasing components were identified and attributed to a single SRS-promoting vibration mode ωSRS = 771.5 cm-1. A short review of melilite-type compounds is given.
TL;DR: In this article, the authors reported the room temperature continuous wave and acousto-optically Q-switched Ho:YAG laser double-pass pumped by a diode-pumped Tm:YLF laser.
Abstract: We report the room temperature continuous wave and acousto-optically Q-switched Ho:YAG laser double-pass pumped by a diode-pumped Tm:YLF laser. Continuous wave output power of 10.5 W at 2090 nm is obtained under the incident pump power of 18.1 W, corresponding to a conversion efficiency of 58.0% and a slope efficiency of 65.7%. For the Q-switched regime the maximum pulse energy of 1.0 mJ and the minimum pulse width of 25 ns at the repetition rate of 10 kHz are achieved, resulting in a peak power of 40.0 kW.
TL;DR: In this article, a simply multiple-wavelength erbium compound ring fiber laser employing a Sagnac interferometer with EDFA and Fabry-Perot laser diode was proposed.
Abstract: We propose and demonstrate experimentally a simply multiple-wavelength erbium compound ring fiber laser employing a Sagnac interferometer with erbium-doped fiber amplifier (EDFA) and Fabry-Perot laser diode (FP-LD). The proposed laser has the advantage of simply structure and easy fabrication, lower insertion loss and cost-effective. Based on the Sagnac fiber laser scheme, the proposed laser can lase eight wavelengths simultaneously. Moreover, the optical output stability of the ring laser has been also discussed.
TL;DR: In this article, a multi-wavelength laser is demonstrated using stimulated Brillouin scattering in a singlemode fiber with a feedback loop using two couplers and an optical circulator.
Abstract: A multi-wavelength laser is demonstrated using stimulated Brillouin scattering in a single-mode fiber with a feedback loop using two couplers and an optical circulator. This Brillouin fiber laser can operate at any wavelength depending on the Brillouin pump (BP) wavelength used. With a BP of 14 dBm, approximately 8 to 10 BFL lines are obtained in both forward and backward directions respectively with a line spacing of 0.16 nm. The use of the 99/1 coupler and 50/50 coupler gives the highest power and number of lines for the forward and backward outputs respectively. The maximum Stokes power obtained is approximately 8.0 dBm. The anti-Stokes lines are also obtained due to four wave mixing and bidirectional operation. The combination of forward and backward output can generate a larger number of lines with channel spacing of 0.08 nm.
TL;DR: A diode-end-pumped acousto-optically Q-switched Nd:YVO4 914 nm laser with 2.4 W output power is reported in this paper.
Abstract: A diode-end-pumped acousto-optically Q-switched Nd:YVO4 914 nm laser with 2.4 W output power is reported for the first time. With intracavity frequency doubling using a 10-mm-long LBO, a maximum 457 nm blue output power of 526 mW is achieved at a repetition rate of 20 kHz. The conversion efficiency from the corresponding Q-switched fundamental output to blue output is 42%. The peak power of the Q-switched blue pulse is up to 175 W with 150 ns pulse duration. The fluctuation of the blue output power is less than 2.0% at the maximum output power.
TL;DR: In this article, continuous-wave output property was detected on several Nd:LuVO4 microchips with different Nd3+ doping level, crystal length, and transmittance of output surface.
Abstract: Nd:LuVO4 crystal was used for the most compact and the simplest laser, i.e. the microchip construction. LD (laser diode)-pumped, continuous-wave output property was detected on several Nd:LuVO4 microchips with different Nd3+ doping level, crystal length, and transmittance of output surface. With a 0.5 at.%, 1.5 mm, T = 1% crystal, 9.7 W maximum output was achieved, corresponding an optical-optical conversion efficiency of 32.0%. With a 1 at.%, 1.5 mm, T = 1% crystal, 9.1 W maximum output was achieved at a pump power of 20.5 W, which had the highest optical-optical conversion efficiency of 44.4%.
TL;DR: Experimental results show that the changes of optical properties caused by glycation of proteins can be observed by refractive index and spectral measurements and can be potentially applied for evaluation of glycated hemoglobin and glycated albumin amount in blood.
Abstract: Monitoring of blood glucose and glycated proteins level is an urgent requirement for diabetic patients. The amount of glycated hemoglobin and glycated albumin depends on blood glucose concentration and reflects the mean glycemia. The purpose of this study is to investigate the effect of presence of glucose and glycation of proteins on optical properties of water solutions of hemoglobin and albumin with different glucose concentrations. We present the results of feasibility study of the refractive index measurements for water solutions of hemoglobin and albumin with glucose by Abbe refractometer. In addition, absorbance spectrum of water solutions of hemoglobin and albumin with different glucose concentrations has been studied. The experimental results show that the changes of optical properties caused by glycation of proteins can be observed by refractive index and spectral measurements. The refractive index measurements can be potentially applied for evaluation of glycated hemoglobin and glycated albumin amount in blood.
TL;DR: In this paper, a simple fiber optic displacement sensor is presented using a multimode plastic bundled fiber and the intensity modulation technique, and the performance of the sensor is compared for different types of probes and targets.
Abstract: A simple fiber optic displacement sensor is presented using a multimode plastic bundled fiber and the intensity modulation technique. The performance of the sensor is compared for different types of probes and targets. The probe with the largest receiving core diameter demonstrates the highest linearity range, and increasing the number of receiving cores increases the sensitivity of the sensor. With a stainless steel target and the concentric bundled fiber with 16 receiving fibers as a probe, the sensitivity of the sensor is found to be 0.0220 mV/μm over 150 to 550 μm range and – 0.0061 mV/μm over 1100 to 2000 μm range. The target with a higher reflectivity shows a higher sensitivity. The linearity range for the front slope is almost similar for all targets tested. However, for the back slope, lower reflectivity objects have a relatively higher linearity range with the highest range of 1600 μm being obtained using plastic and aluminum targets. The simplicity of the design, high degree of sensitivity, dynamic range, non-contact measurement and low cost of the fabrication make it suitable for applications in industries for position control and micro displacement measurement in the hazardous regions.
TL;DR: In this article, an oblique incidence on semiconductor saturable absorber mirror (SESAM) method in the LD pumped passively mode-locked Nd:YVO4 picosecond laser was reported, making SESAM as the intracavity reflecting mirror.
Abstract: We report an oblique incidence on semiconductor saturable absorber mirror (SESAM) method in the LD pumped passively mode-locked Nd:YVO4 picosecond laser in this article, making SESAM as the intracavity reflecting mirror, which produces maximum average output power of 1 W, pulse repetition rate of 120 MHz, and stable continuous mode-locked pulse at 1064 nm with the pulse width of 19.2 ps. To our knowledge, this was the first demonstration that got CW mode-locking in standing-wave laser with a reflected mirror SESAM in oblique incidence way.