Thin-disk Lasers
Author: the photonics expert Dr. Rüdiger Paschotta
Definition: solid-state bulk lasers having a very thin disk of laser-active material as the gain medium
Alternative term: thin-disc lasers
More general term: solid-state lasers
Category: laser devices and laser physics
DOI: 10.61835/u1c Cite the article: BibTex plain textHTML Link to this page
Summary: This in-depth article explains
- how thin-disk lasers are constructed and how they work,
- how multi-pass pumping works and why it is important for such lasers,
- why exactly thermal effects on laser operation are weaker than in other laser types, and in particular why the power scaling properties are much more benign,
- what laser gain media are suitable for thin-disk lasers,
- how spatial hole burning can affect the performance of narrow-linewidth lasers,
- to which extent thin-disk lasers are suitable for pulse generation with Q switching,
- how very high power mode-locked thin-disk lasers can be constructed, also high-power laser amplifiers and lasers with intracavity nonlinear frequency conversion,
- how the thin-disk concept is further developed,
- how thin-disk lasers compete with fiber lasers, and
- how the thin-disk principle is applied to semiconductor disk lasers.
The thin-disk laser (sometimes called thin-disc laser or active-mirror laser) is a special kind of diode-pumped high-power solid-state laser, which was introduced in the 1990s by the group of Adolf Giesen at the University of Stuttgart, Germany [2, 18]. The main difference from conventional rod lasers or slab lasers is the geometry of the gain medium: the laser crystal is a thin disk (see Fig. 1), where the thickness is considerably smaller than the laser beam diameter. The heat generated is predominantly extracted through one end face, i.e., in the longitudinal direction rather than the transverse direction. The cooled end face has a dielectric coating which reflects both the laser radiation and the pump radiation.
The thin disk is also often referred to as an active mirror [1] because it acts as a mirror with laser gain. Within the laser resonator, it can act as an end mirror or as a folding mirror. In the latter case, there are two double passes of the laser radiation per resonator round trip, so the gain per round trip is doubled and the threshold pump power is reduced.
The pump optics (not shown) are arranged for multiple passes of the pump radiation. The heat is extracted in the longitudinal direction, which minimizes thermal lensing effects.
The thin-disk laser should not be confused with the rotary disk laser, where the gain medium is a quickly rotating disk, which is usually a few millimeters thick.
Multipass Pumping
The small thickness of the disk typically leads to inefficient pump absorption when only a single or double pass is used. This problem is normally solved by using a multi-pass pump arrangement, which can be made fairly compact when using a well-designed optical setup, typically containing a parabolic mirror and prism retroreflectors. Such arrangements easily allow one to arrange for e.g. 8 or 16 double passes of the pump radiation through the disk without excessively stringent requirements on the pump beam quality. Compared with high-power fiber lasers, thin-disk lasers have lower demands on the radiance (brightness) of the pump diodes. However, the required radiance is higher than for some slab lasers and other side-pumped lasers.
The pump source of a thin-disk laser is usually based on high-power diode bars, either in fiber-coupled form or with free-space power delivery. A typical pump wavelength is 940 nm for Yb:YAG, whereas ytterbium-doped tungstate crystals can be more efficiently pumped near 981 nm.
Reduced Thermal Issues at High Output Powers; Power Scalability
Due to the small thickness of the disk (e.g. 100–200 μm for Yb:YAG), the temperature rise associated with the dissipated power is minimal. (It is not relevant that the heat generation density is rather high because the heat is generated in close proximity to the heat sink.) In addition, the temperature gradients predominantly occur in a direction perpendicular to the disk surface, resulting in only weak thermal lensing and depolarization loss. This allows for operation with very high beam quality due to the weak thermal beam distortions, and stable operation can be achieved over a wide range of pump powers.
A very important property arising from the thin-disk geometry is power scalability in a strict and meaningful sense. The scaling procedure is simple. For example, the output power can be doubled by applying twice the pump power to twice the area on the disk, while keeping the disk thickness and doping level constant. The laser resonator has to be modified in order to double the mode area in the disk. With this scaling procedure applied, the new design with twice the output power has unchanged peak optical intensities and a nearly unchanged maximum temperature in the disk (the latter essentially because the cooling area has also been doubled). As far as thermal lensing results from the temperature dependence of the refractive index, the dioptric power (inverse focal length) of the thermal lens is reduced to half of its original value. This reduction compensates for the doubled sensitivity of the larger mode to changes in focal length. The power has thus been scaled without increasing optical intensities, the magnitude of temperature rises, or causing thermal lens problems.
A closer inspection reveals that the power scaling may increase the impact of thermal lensing effects due to the additional effects of mechanical stress on the disk. However, that effect can be kept weak enough by keeping the disk thickness small. Another limitation arises from amplified spontaneous emission (ASE) in the transverse direction, which ultimately limits the gain achievable in the longitudinal direction. However, this limitation becomes severe only at very high power levels, specifically with many kilowatts from a single disk. The use of a composite disk with an undoped part on top of the doped part, can effectively suppress ASE; at least for continuous-wave lasers, the ASE limit can be raised to the order of 1 MW from a single disk. Another option is to use multiple thin-disk heads in a single laser resonator (see Figure 2).
So far, around 500 W of output power in a diffraction-limited continuous-wave beam have been obtained with a single disk, or around 1 kW using two disks. In multimode operation, it is possible to achieve more than 4 kW per disk, and for example, 16 kW using four disks in one resonator. Multimode thin-disk lasers with an output power of 16 kW are commercially available, and it seems possible to achieve similar or even higher power levels in nearly diffraction-limited beam.
Power scalability in a wide range is achieved even for passively mode-locked thin-disk lasers (see below). Here, doubling the output power also requires doubling the mode area on the SESAM, so that optical intensities in that device and cooling issues are – contrary to naïve expectations – not limiting factors. Limitations arise from the challenge of implementing dispersion compensation at high power levels. Over 240 W of average output power have been achieved [37, 38]. Even in the 50-fs pulse duration regime, power levels of 100 W and higher have been demonstrated [54, 58].
Thin-disk Gain Media
The most commonly used gain medium for thin-disk lasers is Yb:YAG. Compared to Nd:YAG, it has a shorter emission wavelength (typically 1030 nm), a smaller quantum defect (which reduces the dissipated power), a longer upper-state lifetime (improving energy storage for Q switching), and a larger gain bandwidth (e.g. for shorter pulses with mode locking). It is also beneficial that rather high doping concentrations can be used in order to get sufficiently strong pump absorption. On the other hand, it is a quasi-three-level laser gain medium with significant reabsorption at the laser wavelength, and thus requires higher pump intensities. The thin-disk principle is well-suited for these parameters.
Most thin-disk Yb:YAG lasers operate with pumping around 940 nm, and optical-to-optical efficiencies are often around 50 to 60 %. Even 80 % is possible with pumping at the zero-phonon line (around 970–975 nm) [55].
For broad wavelength tuning and for ultrashort pulse generation, other ytterbium-doped laser gain media offer an even wider gain bandwidth. Examples are tungstate crystals (Yb:KGW, Yb:KYW, Yb:KLuW), Yb:LaSc3(BO3)4 (Yb:LSB), Yb:CaGdAlO4 (Yb:CALGO) and Yb:YVO4. Particularly promising are novel sesquioxide materials such as Yb:Sc2O3 [12], Yb:Lu2O3 [20, 28] and Yb:Y2O3, having excellent thermo-mechanical properties and a potential for very high output powers and high efficiencies. A slope efficiency of 80% has been demonstrated with Yb:Lu2O3 [20]. Research is underway concerning the use of titanium–sapphire disks [42, 44, 45], offering an extremely broad gain bandwidth for pulse generation in the sub-100-fs region.
Nd:YAG or Nd:YVO4 may also be used in thin-disk lasers, e.g. when a wavelength of 1064 nm is required or when the much smaller saturation energy of Nd:YVO4 is relevant.
Generally, a high doping concentration is desirable for thin-disk gain media. This allows one to use a relatively thin disk (and thus to minimize thermal effects) without requiring a very high number of passes of the pump radiation. Most ytterbium-doped laser gain media are quite favorable in this respect. Some gain materials, particularly laser glasses, which exhibit only weak pump absorption and a low thermal conductivity, are not suitable for the thin-disk geometry.
Spatial Hole Burning
An interesting consequence of the small disk thickness is that spatial hole burning usually cannot be avoided, even if a thin-disk laser is built with a ring resonator. (Note that due to the small ratio of thickness and beam radius, counterpropagating waves in the disk always have a strong overlap, resulting in the generation of an interference pattern even in a ring resonator.) Nevertheless, single-frequency operation is possible by using an appropriate wavelength filter (etalon) in the resonator. For passive mode locking (see below), spatial hole burning in the thin disk distorts the shape of the gain spectrum, causing a variety of instabilities. However, it also enables the generation of significantly shorter pulses within the optimum range of parameters [6].
Q-switched Pulse Generation
Thin-disk lasers are well suited for generating high-energy nanosecond pulses with high beam quality, as required for, e.g., some kinds of laser material processing. The typically used gain medium Yb:YAG offers a significantly better energy storage (longer upper-state lifetime) compared with, e.g., Nd:YAG. A limiting factor, however, is the moderate gain (compared with that of an end-pumped rod laser), which makes it difficult to achieve very short (few-nanosecond) pulses with simple Q switching. The combination with cavity dumping is required to obtain rather short pulses.
Mode-locked High-power Thin-disk Lasers
Thin-disk lasers are particularly attractive for the generation of ultrashort pulses at very high power levels. In addition to the high-power capability, the main advantages in this context are
- the ease of achieving diffraction-limited operation (which is a prerequisite for mode locking)
- the broad gain bandwidth of Yb:YAG (the so far most suitable gain medium for thin-disk lasers)
- the very small nonlinearity of a thin disk, which helps to avoid excessive nonlinear phase shifts despite the high intracavity peak intensities
One of the initial challenges was to find a suitable mode-locking mechanism. Even though originally it was widely believed that passive mode locking with semiconductor saturable absorber mirrors (SESAMs) would not be feasible at very high power levels – at least not without first developing special high-power SESAMs, possibly based on improved semiconductor materials –, the author's research group at ETH Zürich demonstrated in 2000 that both thermal and non-thermal issues can be easily managed even at very high power levels, if the design parameters of the overall laser system (and not only of the SESAM) are properly chosen. In other words, SESAM damage does not constitute a limiting factor for the power scaling of mode-locked thin-disk lasers. In fact, it has been found that the mode-locked thin-disk laser is the first truly power-scalable femtosecond laser. However, the design of such lasers involves a number of subtle issues, such as spatial hole burning and thermal challenges in dispersion compensation, and a trial-and-error approach not based on a solid understanding of various details is likely to fail, e.g. by not managing to suppress certain types of instabilities.
Thin-disk lasers have led to the highest average output powers of well over 100 W and, in some cases, even well over 200 W from a mode-locked laser [30, 35, 37]. Pulse energies of > 10 μJ combined with sub-picosecond pulse durations are possible [23, 24, 26], or 80 μJ in picosecond pulses [37].
While typical pulse durations with Yb:YAG are around 700–800 fs, significantly shorter pulses are possible, for example, with ytterbium-doped tungstate crystals such as Yb:KGW or Yb:KYW [8]. Even with Yb:YAG, pulse durations around 200 fs have been demonstrated with Kerr lens mode locking [32, 36, 43, 48].
Amplifiers for High Pulse Energies
Thin-disk laser heads can also be used for regenerative amplifiers [13]. The relatively small gain of the thin disk can be compensated for by increasing the number of resonator round trips. However, this also makes the amplifier more susceptible to optical losses and nonlinearities (e.g. in a Pockels cell). Therefore, it is beneficial to arrange for multiple passes of the signal radiation through the disk during each resonator round trip. Substantial pulse energies are then possible even without using chirped-pulse amplification.
It is also possible to construct a purely multipass amplifier (without a resonator and optical switch), but this approach limits the overall gain and requires a carefully optimized setup in order to preserve a high beam quality.
Nonlinear Frequency Conversion
High-power continuous-wave green lasers can be easily realized in the form of intracavity frequency-doubled thin-disk lasers. For Q-switched or mode-locked lasers, extracavity single-pass frequency doubling is more practical.
Thin-disk lasers are also very interesting pump sources for optical parametric oscillators, amplifiers and generators [7].
A high-power RGB source based on a mode-locked thin-disk laser has also been demonstrated [11]. The high peak power of mode-locked thin-disk lasers enables efficient nonlinear frequency conversion using critical phase matching in LBO crystals. This eliminates the need for temperature-stabilized crystal ovens for most or all conversion stages.
Further Development of the Thin-disk Concept
The thin-disk laser concept allows for further variations. For example, side pumping of the disk may allow for even higher output powers while reducing the requirements on the pump beam quality. This approach, developed at the Lawrence Livermore National Laboratory, is based on a composite laser crystal [22]. An undoped YAG disk, which is bonded to a Yb:YAG disk, offers several advantages. It reduces the beam quality requirements for the pump source, decreases the occurrence of transverse amplified spontaneous emission (ASE) and parasitic lasing in large disks, enhances the mechanical strength, and potentially improves the cooling efficiency. The side-pumped concept may thus allow scaling to much higher powers, even though not necessarily with diffraction-limited beam quality. An interesting option is to use a composite ceramic laser gain medium which is ytterbium doped only in the center region and not in the outside regions, which are used only to deliver the pump power.
It is also interesting to develop cryogenic thin-disk lasers, as cryogenic cooling greatly reduces thermal effects at high power levels. However, that appears to be necessary only for extreme power levels.
Competition with Fiber Lasers
Industrial thin-disk lasers are facing fierce competition from high-power fiber lasers and amplifiers. In continuous-wave operation, those can currently deliver even higher powers in beams that are close to diffraction-limited. Additionally, the wall-plug efficiency can be even higher. Within the next few years, both thin-disk lasers and fiber lasers are expected to make significant further progress. Currently, it is unclear which technology will dominate the market. See also the article on fiber lasers versus bulk lasers.
In the domain of ultrashort pulse generation, fiber amplifier systems based on chirped-pulse amplification allow one to reach even higher average powers and shorter pulse durations than thin-disk lasers can generate without amplification. However, such systems are relatively complex, and thin-disk lasers will probably maintain superiority for the direct generation of pulses with high energies, especially when high pulse quality (concerning temporal shape, low chirp, and stable linear polarization) are required. A key issue in this context is that both the small thickness of the disk and the larger diameter of the beam on the disk lead to a nonlinearity which, compared with that of a fiber laser, is smaller by many orders of magnitude. As a result, in many cases, much simpler techniques can be employed.
A detailed comparison of thin-disk versus fiber lasers is complex and has to take into account many aspects that depend on the specific application. For example, factors such as emission bandwidth, pulse quality, and stability of polarization state can be crucial in certain situations but unimportant in others.
Semiconductor Disk Lasers
The thin-disk geometry is also used in vertical external cavity surface-emitting lasers (VECSELs), a type of surface-emitting semiconductor lasers. A more recent concept is that of the photonic crystal surface-emitting laser.
For such lasers, multiple passes of the pump are usually not required due to the strong absorption of semiconductor materials. However, the concept with multiple pump passes has recently also been applied to such semiconductor lasers, where it allows for a reduced quantum defect and thus for reduced heating and potentially higher powers [14]. To date, it is unclear whether this will lead to more efficient and practical lasers. The original concept has achieved tens of watts of output power without the need for multiple pump passes.
Semiconductor disk lasers will not likely achieve the performance of doped insulator thin-disk lasers, but they are still very interesting. One reason for their interest is that they can be developed for various emission wavelengths, e.g. for blue light generation with intracavity frequency doubling at very high output power levels.
More to Learn
Encyclopedia articles:
Blog articles:
- The Photonics Spotlight 2007-07-25: “Higher Heat Generation Density, Stronger Thermal Effects?”
- The Photonics Spotlight 2011-12-23: “Kerr-lens Mode-locked Thin-disk Laser”
Suppliers
The RP Photonics Buyer's Guide contains five suppliers for thin-disk lasers. Among them:
RPMC Lasers
Serving North America, RPMC Lasers provides a selection of thin-disk lasers, pump modules, gain media, and precision mirror mounts from Dausinger + Giesen, inventors of thin-disk laser technology. This versatile family of thin-disk laser systems provides high pulse energies at high average powers and are suitable for lab or industrial use. These thin-disk regenerative amplifiers offer a range of output specifications to fit various application needs. The base configurations provide 25 W average power with 2.5 mJ pulse energy @ 343 nm (THG), 50 W and 5 mJ @ 515 nm (SHG), and 100W and 100 mJ @ 1030 nm.
Bibliography
[1] | J. A. Abate et al., “Active Mirror: a large-aperture medium repetition rate Nd:glass amplifier”, Appl. Opt. 20 (2), 351 (1981); https://doi.org/10.1364/AO.20.000351 |
[2] | A. Giesen et al., “Scalable concept for diode-pumped high-power solid-state lasers”, Appl. Phys. B 58, 363 (1994); https://doi.org/10.1007/BF01081875 |
[3] | J. Aus der Au et al., “16.2-W average power from a diode-pumped femtosecond Yb:YAG thin disk laser”, Opt. Lett. 25 (11), 859 (2000); https://doi.org/10.1364/OL.25.000859 |
[4] | K. Contag et al., “Theoretical modelling and experimental investigations of the diode-pumped thin disk Yb:YAG laser”, Quantum Electron. 29 (8), 697 (1999); https://doi.org/10.1070/QE1999v029n08ABEH001555 |
[5] | C. Stewen et al., “A 1-kW CW thin disc laser”, J. Sel. Top. Quantum Electron. 6 (4), 650 (2000); https://doi.org/10.1109/2944.883380 |
[6] | R. Paschotta et al., “Passive mode locking of thin-disk lasers: effects of spatial hole burning”, Appl. Phys. B 72 (3), 267 (2001); https://doi.org/10.1007/s003400100486 |
[7] | T. Südmeyer et al., “Novel ultrafast parametric systems: high repetition rate single-pass OPG and fiber-feedback OPO”, J. Phys. D: Appl. Phys. 34 (16), 2433 (2001); https://doi.org/10.1088/0022-3727/34/16/307 |
[8] | F. Brunner et al., “240-fs pulses with 22-W average power from a mode-locked thin-disk Yb:KY(WO4)2 laser”, Opt. Lett. 27 (13), 1162 (2002); https://doi.org/10.1364/OL.27.001162 |
[9] | E. Innerhofer et al., “60 W average power in 810-fs pulses from a thin-disk Yb:YAG laser”, Opt. Lett. 28 (5), 367 (2003); https://doi.org/10.1364/OL.28.000367 |
[10] | R. Paschotta et al., “Passively mode-locked thin-disk laser”, U.S. Patent 6,834,064 (2004) |
[11] | F. Brunner et al., “Powerful RGB laser source pumped with a mode-locked thin-disk laser”, Opt. Lett. 29 (16), 1921 (2004); https://doi.org/10.1364/OL.29.001921 |
[12] | P. Klopp et al., “Highly efficient mode-locked Yb:Sc2O3 laser”, Opt. Lett. 29 (4), 391 (2004); https://doi.org/10.1364/OL.29.000391 |
[13] | A. Beyertt et al., “Femtosecond thin-disk Yb:KYW regenerative amplifier”, Appl. Phys. B 80, 655 (2005); https://doi.org/10.1007/s00340-005-1796-3 |
[14] | S. -S. Beyertt et al., “Optical in-well pumping of a semiconductor disk laser with high optical efficiency”, IEEE J. Quantum Electron. 41 (12), 1439 (2005); https://doi.org/10.1109/JQE.2005.858794 |
[15] | T. Dascalu and T. Taira, “Highly efficient pumping configuration for microchip solid-state laser”, Opt. Express 14 (2), 670 (2006); https://doi.org/10.1364/OPEX.14.000670 |
[16] | S. V. Marchese et al., “Pulse energy scaling to 5 μJ from a femtosecond thin-disk laser”, Opt. Lett. 31 (18), 2728 (2006); https://doi.org/10.1364/OL.31.002728 |
[17] | C. Stolzenburg et al., “Cavity-dumped intracavity-frequency-doubled Yb:YAG thin-disk laser with 100 W average power”, Opt. Lett. 32 (9), 1123 (2007); https://doi.org/10.1364/OL.32.001123 |
[18] | A. Giesen and J. Speiser, “Fifteen years of work on thin-disk lasers: results and scaling laws”, J. Sel. Top. Quantum Electron. 13 (3), 598 (2007); https://doi.org/10.1109/JSTQE.2007.897180 |
[19] | R. Paschotta, J. Speiser, and A. Giesen, “Comment on 'Surface loss limit of the power scaling of a thin-disk laser'”, J. Opt. Soc. Am. B 24 (10), 2658 (2007); https://doi.org/10.1364/JOSAB.24.002658 |
[20] | R. Peters et al., “Broadly tunable high-power Yb:Lu2O3 thin disk laser with 80% slope efficiency”, Opt. Express 15 (11), 7075 (2007); https://doi.org/10.1364/OE.15.007075 |
[21] | S. V. Marchese et al., “Efficient femtosecond high power Yb:Lu2O3 thin-disk laser”, Opt. Express 15 (25), 16966 (2007); https://doi.org/10.1364/OE.15.016966 |
[22] | J. Vetrovec et al., “Side-pumped solid-state disk laser for high-average power ”, U.S. Patent 7 200 161 |
[23] | J. Neuhaus et al., “Passively mode-locked Yb:YAG thin-disk laser with pulse energies exceeding 13 μJ by use of an active multipass geometry”, Opt. Lett. 33 (7), 726 (2008); https://doi.org/10.1364/OL.33.000726 |
[24] | S. V. Marchese et al., “Femtosecond thin-disk laser oscillator with pulse energy beyond the 10-microjoule level”, Opt. Express 16 (9), 6397 (2008); https://doi.org/10.1364/OE.16.006397 |
[25] | G. Palmer et al., “Passively mode-locked Yb:KLu(WO4)2 thin-disk oscillator operated in the positive and negative dispersion regime”, Opt. Lett. 33 (14), 1608 (2008); https://doi.org/10.1364/OL.33.001608 |
[26] | J. Neuhaus et al., “Subpicosecond thin-disk laser oscillator with pulse energies of up to 25.9 microjoules by use of an active multipass geometry”, Opt. Express 16 (25), 20530 (2008); https://doi.org/10.1364/OE.16.020530 |
[27] | J. Speiser, “Scaling of thin-disk lasers – influence of amplified spontaneous emission”, J. Opt. Soc. Am. B 26 (1), 26 (2009); https://doi.org/10.1364/JOSAB.26.000026 |
[28] | C. R. E. Baer et al., “Femtosecond Yb:Lu2O3 thin disk laser with 63 W of average power”, Opt. Lett. 34 (18), 2823 (2009); https://doi.org/10.1364/OL.34.002823 |
[29] | T. Südmeyer et al., “High-power ultrafast thin disk laser oscillators and their potential for sub-100-femtosecond pulse generation”, Appl. Phys. B 97 (2), 281 (2009); https://doi.org/10.1007/s00340-009-3700-z |
[30] | C. R. E. Baer et al., “Femtosecond thin-disk laser with 141 W of average power”, Opt. Lett. 35 (13), 2302 (2010); https://doi.org/10.1364/OL.35.002302 |
[31] | S. Ricaud et al., “Yb:CaGdAlO4 thin-disk laser”, Opt. Lett. 36 (21), 4134 (2011); https://doi.org/10.1364/OL.36.004134 |
[32] | O. Pronin et al., “High-power 200 fs Kerr-lens mode-locked Yb:YAG thin-disk oscillator”, Opt. Lett. 36 (24), 4746 (2011); https://doi.org/10.1364/OL.36.004746 |
[33] | C. J. Saraceno et al., “Sub-100 femtosecond pulses from a SESAM modelocked thin disk laser”, Appl. Phys. B 106 (3), 559 (2012); https://doi.org/10.1007/s00340-012-4900-5 |
[34] | C. R. E. Baer et al., “Frontiers in passively mode-locked high-power thin disk laser oscillators”, Opt. Express 20 (7), 7054 (2012); https://doi.org/10.1364/OE.20.007054 |
[35] | D. Bauer et al., “Mode-locked Yb:YAG thin-disk oscillator with 41 μJ pulse energy at 145 W average infrared power and high power frequency conversion”, Opt. Express 20 (9), 9698 (2012); https://doi.org/10.1364/OE.20.009698 |
[36] | O. Pronin et al., “High-power Kerr-lens mode-locked Yb:YAG thin-disk oscillator in the positive dispersion regime”, Opt. Lett. 37 (17), 3543 (2012); https://doi.org/10.1364/OL.37.003543 |
[37] | C. J. Saraceno et al., “Ultrafast thin-disk laser with 80 μJ pulse energy and 242 W of average power”, Opt. Lett. 39 (1), 9 (2014); https://doi.org/10.1364/OL.39.000009 |
[38] | J. Brons et al., “Energy scaling of Kerr-lens mode-locked thin-disk oscillators”, Opt. Lett. 39 (22), 6442 (2014); https://doi.org/10.1364/OL.39.006442 |
[39] | C. J. Saraceno et al., “Toward millijoule-level high-power ultrafast thin-disk oscillators”, IEEE J. Sel. Top. Quantum Electron. 1 (1), 1100318 (2015) |
[40] | H. Fattahi et al., “High-power, 1-ps, all-Yb:YAG thin-disk regenerative amplifier”, Opt. Lett. 41 (6), 1126 (2016); https://doi.org/10.1364/OL.41.001126 |
[41] | J. Fischer et al., “615 fs pulses with 17 mJ energy generated by an Yb:thin-disk amplifier at 3 kHz repetition rate”, Opt. Lett. 41 (2), 246 (2016); https://doi.org/10.1364/OL.41.000246 |
[42] | V. Chvykov et al., “High peak and average power Ti:sapphire thin disk amplifier with extraction during pumping”, Opt. Lett. 41 (13), 3017 (2016); https://doi.org/10.1364/OL.41.003017 |
[43] | J. Brons et al., “Powerful 100-fs-scale Kerr-lens mode-locked thin-disk oscillator”, Opt. Lett. 41 (15), 3567 (2016); https://doi.org/10.1364/OL.41.003567 |
[44] | R. S. Nagymihaly et al., “Liquid-cooled Ti:Sapphire thin disk amplifiers for high average power 100-TW systems”, Opt. Express 25 (6), 6664 (2017); https://doi.org/10.1364/OE.25.006664 |
[45] | J.-H. Wolter et al., “Thin-disk laser operation of Ti:sapphire”, Opt. Lett. 42 (8), 1624 (2017); https://doi.org/10.1364/OL.42.001624 |
[46] | T. Nubbemeyer et al., “1 kW, 200 mJ picosecond thin-disk laser system”, Opt. Lett. 42 (7), 1381 (2017); https://doi.org/10.1364/OL.42.001381 |
[47] | C. Paradis et al., “Generation of 35-fs pulses from a Kerr lens mode-locked Yb:Lu2O3 thin-disk laser”, Opt. Express 25 (13), 14918 (2017); https://doi.org/10.1364/OE.25.014918 |
[48] | J. Zhang, K. F. Mak, and O. Pronin, “Kerr-lens mode-locked 2 μm thin-disk lasers”, IEEE J. Sel. Top. Quantum Electron. 24 (5), 1 (2018); https://doi.org/10.1109/JSTQE.2018.2814780 |
[49] | J. Zhang et al., “High-power, high-efficiency Tm:YAG and Ho:YAG thin-disk lasers”, Laser & Photonics Reviews 12 (3), 1700273 (2018); https://doi.org/10.1002/lpor.201700273 |
[50] | F. Saltarelli et al., “Power scaling of ultrafast oscillators: 350-W average-power sub-picosecond thin-disk laser”, Opt. Express 27 (22), 31465 (2019); https://doi.org/10.1364/OE.27.031465 |
[51] | R.-A. Lorbeer et al., “Monolithic thin-disk laser and amplifier concept”, Optica 7 (10), 1409 (2020); https://doi.org/10.1364/OPTICA.402164 |
[52] | S. Nagel et al., “Thin-disk laser system operating above 10 kW at near fundamental mode beam quality”, Opt. Lett. 46 (5), 965 (2021); https://doi.org/10.1364/OL.416432 |
[53] | J. Drs et al., “Sub-30-fs Yb:YAG thin-disk laser oscillator operating in the strongly self-phase modulation broadened regime”, Opt. Express 29 (22), 35929 (2021); https://doi.org/10.1364/OE.440196 |
[54] | J. Fischer et al., “Efficient 100-MW, 100-W, 50-fs-class Yb:YAG thin-disk laser oscillator”, Opt. Express 29 (25), 42075 (2021); https://doi.org/10.1364/OE.442833 |
[55] | A. Alabbadi, M. Larionov and F. Fink, “High-power Yb:YAG thin-disk laser with 80% efficiency pumped at the zero-phonon line”, Opt. Lett. 47 (1), 202 (2022); https://doi.org/10.1364/OL.444245 |
[56] | S. Tomilov et al., “50-W average power Ho:YAG SESAM-modelocked thin-disk oscillator at 2.1 µm”, Opt. Express 30 (15), 27662 (2022); https://doi.org/10.1364/OE.460298 |
[57] | M. Seidel, L. Lang, C. R. Phillips and U. Keller, “Influence of disk aberrations on high-power thin-disk laser cavities”, Opt. Express 30 (22), 39691 (2022); https://doi.org/10.1364/OE.474183 |
[58] | S. Goncharov, K. Fritsch and O. Pronin, “110 MW thin-disk oscillator”, Opt. Express 31 (16), 25970 (2023); https://doi.org/10.1364/OE.491938 |
[59] | J. Drs et al., “A decade of sub-100-fs thin-disk laser oscillators”, Laser & Photonics Reviews 8 (17), 2200258 (2023); https://doi.org/10.1002/lpor.202200258 |
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