- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
High-power operation of double-pass pumped Nd:YVO <sub/>4</sub> thin disk laser
摘要： A simple, compact, double-pass pumped Nd:YVO4 thin disk laser is demonstrated. Its continuous-wave performance with different Nd doping concentrations and thicknesses is investigated experimentally. The maximum output power of 17.7 W is achieved by employing a 0.5 at.% doped sample, corresponding to an optical-to-optical ef?ciency of 46% with respect to the absorbed pump power. In addition, a numerical analysis and an experimental study of the temperature distribution, and thermal lens effect of the Nd:YVO4 thin disk, are presented considering the in?uence of the energy transfer upconversion effect and the temperature dependence of the thermal conductivity tensor. The simulated results are in good agreement with the experimental results.
关键词： energy transfer upconversion effect,Nd:YVO4,thin disk laser,thermal lens effect
更新于2025-09-23 15:19:57
-
[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Milliwatt-Class MHz Repetition-Rate THz Source Driven by a sub-100 fs High Power Thin-Disk Laser
摘要： We demonstrate optical rectification in GaP crystals thin-disk oscillator, nonlinearly driven by a 100 W-class compressed to sub-100 fs in a multi-pass cell. In optimized conditions, we obtain a power of 1.35 mW, which is the highest average power achieved in GaP so far. Additionally, we explore the effect of temperature of the crystal down to 77 K, showing that controlling the temperature of the crystal could be a key aspect for further power scaling and for handling thermal effects that become important at such high driving powers.
关键词： thin-disk laser,optical rectification,THz source,GaP crystals,high power
更新于2025-09-16 10:30:52
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - High-Power 0.33 mW Broadband THz Source Driven by an Ultrafast Yb-Based Thin-Disk Laser Oscillator
摘要： THz-time-domain spectroscopy (THz-TDS) is a well-established tool for characterizing material properties and investigating dynamics of complex molecular systems. As the broadband THz generation typically relies on sub-100-fs laser pulses, most systems are currently driven by Ti:sapphire lasers. In the last years there has been a strong effort to replace Ti:sapphire systems with power-scalable Yb-based directly diode-pumped solid-state lasers (DPSSLs). Ultrafast DPSSLs generate higher average power with lower complexity and better efficiency. However, their potential for high-power broadband THz operation has not yet been fully exploited. This study shows the high potential of TDL oscillator driven systems for high-power broadband THz generation. Thanks to the power scalability of the TDL technology we expect broadband THz sources operating at MHz repetition rates and several mW average power to be soon within reach.
关键词： THz-time-domain spectroscopy,thin-disk laser oscillator,broadband THz generation,Yb-based lasers
更新于2025-09-16 10:30:52
-
[IEEE 2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS) - Tel-Aviv, Israel (2019.11.4-2019.11.6)] 2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS) - Terahertz Range Elementary Dipole Excitation of a Thin Dielectric Disk Sandwiched between Two Graphene Covers: Integral Equation Analysis
摘要： We study, using the integral equation technique, the scattering of the field radiated by an elementary dipole, by a thin dielectric disk sandwiched between two conformal graphene covers, on the top and bottom faces. To build a mathematical model of such scatterer, we use the generalized boundary condition in the form first obtained by Mitzner and Bleszynski et al. and generalized by Karlsson. This enables us to derive dual integral equations in the disk plane for the Hankel transforms of the tangential electric and magnetic field components, and cast it to a set of two coupled Fredholm second-kind integral equations. The latter equations are discretized and solved numerically with the guaranteed convergence. We compute and plot the power radiated by an elementary magnetic dipole placed above such a composite disk, in the THz range. This reveals that the studied scatterer is a complicated open resonator supporting the low-frequency plasmon modes and the high-frequency dielectric-disk modes.
关键词： generalized boundary condition,radiated power,thin disk,graphene,plasmon resonances
更新于2025-09-16 10:30:52
-
Investigation of spectrally-dependent phonon relaxation mechanism in Yb:YAG gain media and its consequences for thin disk laser performance
摘要： Nonlinear phonon relaxation in Yb:YAG gain media has previously been investigated, and a hypothesis correlating photo-induced free electrons and heat generation in crystals pumped at a wavelength of 940 nm was established (Brandt et al 2011 Appl. Phys. B 102 765–8). Later, we demonstrated efficient suppression of nonlinear phonon relaxation by zero-phonon line (ZPL) pumping of Yb:YAG (969 nm). However, no hypothesis has yet been tested that correlates the heat load and the free electrons in Yb:YAG media. We investigate, both theoretically and experimentally, the behaviour of an Yb:YAG slab pumped by a high-power laser diode at a conventional broadband line (absorption maximum at 941 nm) and a ZPL (absorption maximum at 969 nm), and we compare the generated photocurrent, temperature, and absorbed pump power for those two pump wavelengths. Although the hypothesis established by Brandt et al (2011 Appl. Phys. B 102 765–8) was not confirmed, and the measured photocurrent was identical for the two pump wavelengths, our measurement contributes to the knowledge of the inner processes in Yb:YAG active media. In the following steps we characterized an Yb:YAG thin disk laser, measured the spectrally-resolved absorption and disk surface temperature, and optimised our predictive model of thin disk behaviour. All the experimental and theoretical results are reported.
关键词： numerical modelling,thin disk,thermal effects,Yb:YAG,photocurrent
更新于2025-09-16 10:30:52
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Thin-Disk Laser Emitting Beams with 980 W of CW-Output Power and Radial Polarization
摘要： Within the past decade, a variety of scientific groups have demonstrated the potential of radially and azimuthally polarized laser beams in many applications [1-3]. Experimental investigations in high-power operation indicate additional beneficial properties for material processing, such as drilling and deep-penetration-welding, which have been demonstrated to lead to an increase of the process efficiency by using such a polarization state. Cutting of metal sheets with radially polarized beams at 1 micron wavelength have been reported recently to increase the process efficiency [4]. In the present work, we report on the generation of radially polarized laser beams in cw operation by using grating-waveguide mirror (GWM) [5]. The grating design is based on the leaky-mode coupling mechanism, which allows for sufficient reduction of the reflectivity of the polarization state (azimuthal or radial) to be suppressed in the resonator. It consists of a circular sub-wavelength diffraction grating integrated into a highly or partially reflective dielectric multilayer mirror. At the central wavelength of the Yb:LuAG TDL, i.e., at 1030 nm, the absolute values of the reflectivities for the TE- and TM-polarized light were measured to be (55.2 ± 0.2)% and (99.8 ± 0.2)%, respectively. This corresponds to a reflectivity difference of approximately 45%. At wavelengths of 1023, 1042, and 1059 nm, the reflectivity of the TE-polarized beam was measured to be <1%, making the grating attractive for other applications with lasers operating within this wavelength range. The grating was implemented as cavity end mirror in an Yb:LuAG thin-disk laser setup, pumped at its “zero-phonon” line, i.e. λ = 969 nm. The implementation of the GWM led to the extraction of a radially polarized beam with an output power of 980 W and an optical efficiency of 50.5%. Single transversal mode operation of a radially polarized LG01 mode was sustained for the whole output power range with beam quality factors of Mx2 = 2.0 and My2 = 2.3. Figure 1(a) shows a photograph of the GWM. In Fig. 1(b), the performance of the laser and the far field intensity distribution of the emitted laser beam is shown. A qualitative analysis of the polarization was carried out by recording the intensity distributions transmitted through a rotating polarizer at different orientations of its transmission axis. Furthermore, the purity of polarization (degree of polarization) was measured with a custom-made camera-based 2D Stokes-polarimeter. An average degree of radial polarization of 95% was measured.
关键词： grating-waveguide mirror,high-power operation,radially polarized laser beams,material processing,Yb:LuAG thin-disk laser
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Towards a kW-Class Picosecond Laser at 1 kHz
摘要： Secondary sources development such as X-rays for medical applications demand diode-pumped high-energy, high-power and high repetition rate picosecond lasers leading to a race to the kW milestone. Year after year, the pulse energy increased to few hundreds of millijoules at 1 kHz [1], but all the kW systems are based on the Yb:YAG thin disk technology which until now, to the best of our knowledge, has come short to deliver the full kilowatt level at 1 kHz. On the other side, cryogenically cooled bulk Yb:YAG amplifiers has shown its capabilities to reach 1 J at 500 Hz with 3.8 ps pulses [2]. Since two years, CELIA has launched new technology developments for a new system (HORIZON) aiming to reach 1 J, 1 kHz, 1 ps. We selected Yb:YAG crystal as laser gain medium since its thermal properties and its low quantum defect are suitable for high power laser generation. However, its narrow spectral bandwidth and its high saturation fluence impose large constraints on both the amplifier and compressor architectures. Cutting-edge technologies such as hypercompressor [3], divided pulse amplification [4], thin-disk and liquid-cooled disks are explored to address these limitations.
关键词： thin disk technology,cryogenically cooled bulk Yb:YAG amplifiers,high repetition rate,high-power,divided pulse amplification,hypercompressor,picosecond lasers,Yb:YAG,high-energy
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Thin Disk Laser Operating in Fundamental Mode up to a Power of 4kW
摘要： Fundamental mode lasers at high power are desirable to accommodate many industrial and scientific applications especially in pulsed mode of operation. Due to its unique properties the thin disk laser (TDL) concept is an ideal platform for the generation of high optical power with excellent beam quality. Reliability, low brightness constraints for the pump source, insensitivity to back reflections, negligible nonlinearities, high scalability are a few inherent properties, and thus TDLs have been widely used in industrial applications. In the past there have been many efforts to reach the maximum output power keeping the beam quality close to the diffraction limit. Here we report on an enhanced system reaching 4 kW output power with a beam quality M2<1.2 over the full power range. The experimental setup consists of a multipass pump chamber which enables 22 passes through the active laser disk, two convex high-reflection (HR) mirrors, a spherically deformable mirror (SDM), an Yb-doped laser disk mounted on a heat sink and an outcoupling (OC) mirror. The OC is shaped such that static aspherical wavefront aberrations originating from the laser disk can be compensated. Using this approach, we demonstrate a 4 kW diffraction limited building block. Further power scaling can be achieved by using conventional combining methods such as polarization beam combining, spatial beam combining or disk multipass amplification.
关键词： high power,beam quality,thin disk laser,fundamental mode,diffraction limit
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - High-Power Dual-Comb Thin-Disk Oscillator
摘要： Dual-comb spectroscopy is a rapidly advancing spectrometric technique where the temporal interferograms generated with two asynchronous trains of pulses are recorded, and Fourier transformed to reveal the spectrum of an absorber in the beam path [1]. To date, best performance is achieved with systems involving complex active stabilization of two femtosecond erbium fiber lasers [1]. One way to simplify the technique is to generate a dual-comb output from a single laser cavity. However, there have been only a few demonstrations of such a scheme so far [2,3]. Here we present a dual-comb system based on a single thin-disk oscillator. The novel architecture effectively rejects common noise, with mutual coherence time exceeding one second without any active stabilization. Moreover, the system shows nearly an order of magnitude higher average and peak output powers compared to previous dual-comb demonstrations. Efficient nonlinear frequency conversion to the UV or mid-IR regions—of high interest to molecular spectroscopy—will thus be greatly facilitated.
关键词： thin-disk oscillator,high-power,Yb:YAG,Kerr-lens mode-locked,dual-comb spectroscopy
更新于2025-09-11 14:15:04
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Power-Scaling Nonlinear-Mirror Modelocked Thin-Disk Lasers
摘要： High-power ultrafast laser sources constitute a key technology to a wide variety of scientific and industrial applications that benefit from the combination of high average power and sub-ps pulse duration. While coherently combined amplifier systems now deliver kW-level average powers, ultrafast thin-disk lasers (TDLs) remain of considerable interest as compact, low-noise laser sources delivering multi-hundred-Watts with excellent beam quality. These oscillators are usually modelocked using either of two well-established techniques: SESAM or Kerr-lens modelocking (KLM). Recently, we demonstrated the first TDL modelocked using the frequency-doubling nonlinear mirror (NLM). This technique relies on the combination of an intracavity χ(2) crystal used for second-harmonic generation (SHG) and a dichroic output coupler mirror (OC) that is highly reflective for the second harmonic (SH) and partially reflective for the fundamental wave (FW). The NLM device (SHG crystal + dichroic OC) thus provides a saturable reflectivity enabling modelocked operation. Our first NLM-modelocked TDL delivered <30 W with pulse durations >323 fs at a repetition rate of 17.8 MHz. Here we present a power-scaled NLM-modelocked TDL delivering 66 W and 430 fs pulses at 9.3 MHz, and up to 87 W and 586 fs pulses at 8.9 MHz. We thereby improve the output average power by a factor ≈3 and the peak power by a factor ≈5. This corresponds to 3 orders of magnitude more peak power than NLM results based on bulk-crystal lasers. We furthermore identify stable modelocking regimes that avoid Q-switching instabilities.
关键词： modelocking,thin-disk lasers,ultrafast lasers,nonlinear mirror,power scaling
更新于2025-09-11 14:15:04