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Ultrafast dynamics experiments in physics, chemistry and biology, in condensed matter or gas phase require different types of ultrafast laser sources. Class 5 Photonics builds high-power optical parametric chirped pulse amplifiers (OPCPA) which are a powerful toolbox to deliver femtosecond pulses from
the UV to MIR spectral range.
2D Infrared spectroscopy (2DIR) / PEEMS / tr-ARPES / Multi-color pump-probe, Mid-IR and THz spectroscopy / Magneto-optical Kerr-effect (MOKE) microscopy / Raman spectroscopy / HHG, x-ray and electron spectroscopy
Generally, research laboratories focused on ultrafast phenomena require robust and flexible laser systems in order to drive a variety of experiments. Previously, laser sources were driven from Ti:Sapphire lasers at 800 nm with limited spectral bandwidth (Fourier limited pulse of ca. 20 fs), and more importantly limited power levels and repetition rates. Commonly available systems were achieving a few microjoules at 100 kHz repetition rate, or a few millijoules at 1 kHz repetition rate.
However, for many applications high repetition rates in the MHz range are needed to increase the signal-to-noise ratio. At the same time, driving nonlinear interactions requires sufficient pulse energies up to the millijoule range. The recent advances in Yb-based lasers brought a new generation of high-power scientific lasers to the community, however, also at limited spectral bandwidth (Fourierlimited pulses of 200-2000 fs). Optical parametric chirped-pulse amplication (OPCPA) together with bulk crystal white-light-generation (WLG) opens up the possibility for ultrashort (< 10 fs), high-power lasers with average power up to 100 W, repetition rates of 100 kHz in the millijoule-range or up to 10 MHz in the microjoule-range. Further, a wide wavelength range is accessible from ultraviolet (UV) to mid-infrared (MIR), making OPCPA an ideal technology for realizing complex pump-probe architectures, including secondary sources, such as terahertz and extreme ultraviolet high-harmonic generation (HHG).
Example: PEEMS
The White Dwarf for ultrafast material science is a compact OPCPA system developed by Class 5 Photonics to provide two synchronized outputs that can be individually spectrally tuned at a repetition rate of 4 MHz. The complete system is realized in a single housing on a footprint of 800 mm x 1200 mm, including the pump laser (Coherent Monaco-1035-80-60). A first output is tunable between 650 and 1300 nm, with corresponding SHG output between 325 and 650 nm in order to achieve gap-less excitation from 325 to 1300 nm. A second output for probing is tunable between 650 and 950 nm (fundamental wavelength), with a second-harmonic generation stage (SHG) providing wavelengths between 325 and 475 nm, and a third-harmonic generation stage (THG) providing UV wavelengths between 250 and 316 nm. The outputs achieve up to 3 W of average power in each of the fundamental outputs, 0.9 W in the SHG, and 0.3 W in the THG with pulse durations between 30 and 50 fs. The system includes full monitoring and diagnostics to ensure reliability, long-term robustness and user friendliness. 
Example: Pump-Probe System from THz to XUV
The White Dwarf HE is a high-power, femtosecond laser system customizable to span an ultra wide frequency range from Terahertz (THz) to extreme-ultraviolet (XUV). The system can be used for long-wavelength excitation of carrier dynamics and short-wavelength (XUV) probing of excited photoelectrons, with suficient probing photon energy of 21.6 eV to cover the full Brillouin-zone of a solid-state material. The White Dwarf HE OPCPA is based on a 350 W Yb-based picosecond laser, which pumps three synchronized outputs: a high-field THz generation source, two individually tunable optical parametric chirped-pulse ampliers (OPCPA 1+2, 3), a second- and fourth-harmonic generation (SHG and FHG) source, and a high-harmonic generation source (HHG). 
Example: THz-generation in organic crystals
The excitation of low energy modes in matter plays a key role in advanced material studies. A commonly used generation process for high-field THz-pulses is optical rectification, which is a second-order nonlinear process. Recently developed organic nonlinear crystals, such as DAST and DSTMS feature a high transparency and a large nonlinear coefficient. Using driver laser pulses centered at 1.55 µm allows for an easier collinear phase-matching scheme. The White Dwarf HE OPCPA concept was extended to a tunable, high power laser system centered at a wavelength of 1.55 µm providing e.g. 30 µJ, sub 36 fs at 350 kHz. In addition, an optically synchronized compressed probe pulse with pulse duration of < 15 fs at 850 nm, was made available as a second output. This probe-pulse can be used, e.g. for electro-optical sampling in a THz set-up. The White Dwarf HE OPCPA can be pumped by a standard industrial Yb-based laser system with up to 300 W.
Example: Ultrafast dynamics in the water window (200-550 eV)
High-harmonic generation (HHG) spectroscopy and associated photoionization spectroscopy in the soft-x-ray regime have been successfully proven as a technique to resolve fundamental strong-field phenomena and electron dynamics on the attosecond scale. To scale the generated photon energy cut off, mid-infrared laser drivers are beneficial. Additionally, the majority of the measurements are subject to long integration times due to the weak light-matter interaction cross-sections in the experimental target and the detection technologies. Hence, higher repetition rates are required. Class 5 Photonics further develops the high-power Supernova OPCPA system to provide a CEP-stable HHG laser driver at a wavelength of 2 µm at a repetition rate of 50 kHz, and a pulse duration of < 30 fs. Currently, the system is under commissioning achieving more than 47 W (940 µJ at 50 kHz). 
Class 5 Photonics sponsored the "Ultrafast Phenomena and Nanophotonics" session at Photonics West 2020. Parts of the results described above have been presented at the corresponding conference.
Please, find more information in the manuscripts:
We are back on the exhibition and conference floor. Our distributor from hoch laser will proudly present our products and technology at LASER World of PHOTONICS CHINA in Shanghai.
Visit Hall 8.1 B307 and learn about Class 5 Photonics' high-power OPCPA systems to accelerate your research. 
CLEO is around the corner and will be held fully online. Accessible without registration fee! Take this chance and engage within the Laser Science and Photonic Applications community. Class 5 Photonics will present a talk and a poster: High-power OPCPAs at 1.45 – 2.4 μm and up to 100 W power scalability (SF1H.7) presented by our CEO Dr. Robert Riedel Session: Ultrafast Parametric Sources (SF1H) Friday 9:45 - 10:00 -- watch recorded session here with Robert's presentation starting at 1h:42min, download manuscript here Dual-channel laser system with gap-less tuning from 250 to 1300 nm at megahertz repetition rates for time-resolved photoelectron-emission microscopy and spectroscopy (JW2F.22) presented by our CTO Dr. Michael Schulz Session: Joint Poster Session 11 (JW2F) Wednesday 15:15-16:45 -- watch recorded session here with Michaels presentation starting at minute 30. Get in touch with us and ask your questions despite the exhibitor programm was canceled. We are looking forward to meet you online!  Some good news and some bad news… Just before the coronavirus disease arrived to Europe Class 5 Photonics shipped its very first system to Asia - namely South Korea. We are proud to reach the Asian market and to serve scientists world-wide with our high-power OPCPA systems made in Germany. The shipped White Dwarf OPCPA is a compact (80 cm x 80 cm) one-box laser system incorporating a 40 W Coherent Monaco industrial laser and the Class 5 Photonics' high-power optical parametric chirped-pulse amplifier (OPCPA). This unique combination provides turnkey access to few-cycle pulse widths < 9 fs at 800 nm, with pulse energies > 4 μJ and 1 MHz repetition rate, featuring excellent long-term output stability. The White Dwarf system is ideal for applications ranging from attosecond science to ultrafast electron diffraction and multidimensional spectroscopy. Our little package already arrived at Korea and now the system is waiting for its installation in the Customer's lab. Unfortunately, the current situation of world-wide Corona infections, quarantine and travel bans will postpone the installation. We are patient until then and look forward to rock the customer’s new lab when the White Dwarf OPCPA gets finally installed (we keep you posted).  Proud Laser Engineers a few weeks ago with packaged White Dwarf OPCPA system.
Customer lab in South Korea with White Dwarf OPCPA waiting for its installation. Normalized spectral intensity: White Dwarf OPCPA WD-800, central wavelength ca. 800 nm, 4 W average power, 1 MHz repetition rate, Pump laser Coherent Monaco 40 W. Retrieved temporal intensity profile measured via SHG-FROG: White Dwarf OPCPA WD-800, central wavelength ca. 800 nm, pulse duration FWHM 8.9 fs, 4 W average power, 1 MHz repetition rate, Pump laser Coherent Monaco 40 W. UPDATE: This conference got cancelled. We are going to present the latest results of our 100 W-level Supernova OPCPA at DPG Tagung in Hannover. Come and discuss with us about extreme power at extreme wavelength. Unfortunately, we will not be present with a booth this time, but we are anyway around and are looking forward to some interessting discussions about high-power femtosecond lasers and applications. See you there!  Our cto michael presented at spie Photonics west our tunable White Dwarf OPCPA from 250-1300 nm2/19/2020
Our CTO Michael presented at the SPIE Photonics West 2020 conference our latest developments: A dual channel laser system with gap-less tuning from 250 to 1300 nm at megahertz repetition rates for time resolved photoelectron emission microscopy and spectroscopy. Based on the success story of our White Dwarf OPCPA with high performance operation at a single wavelength, we now also provide tunable solutions for demanding spectroscopy and microscopy applications. Ultrashort pulses (< 30 fs) are delivered in a spectral range from 650 to 1300 nm. This makes the White Dwarf WD-800-tunable the most flexible non-colinear OPA on the market. Additionally, the wavelength range can be further extended to the UV via second harmonic (SHG) and third harmonic generation (THG). Due to our gap-less approach, material scientists have access to the green wavlength range (500 nm) and can, for example, study the transport of carriers excited by a green pump pulse. Equipped with two outputs, our White Dwarf WD-800-tunable-dual offers two synchronized channels and enables pump-probe studies. Thus, time-resolved ARPES or PEEMS benefit from our very flexible solution while maintaining high temporal resolution to study ultrafast dynamics in materials. Our White Dwarf WD-800-tunable can operate at 1, 2 or 4 MHz for fast image acquisition and to suppress space charge effects. A pulse-picker of the integrated pump laser (Coherent Monaco 60 W incl.) can be used to reduce the repetition rate in alignment mode or for lower average power operation.  CTO Jose Pozo of EPIC (European Photonics Industry Consortium) interviewed our CEO Robert Riedel who shared some insights of Class 5 Photonics' journey from the early beginnings to the future.
Robert explains why Class 5 Photonics provides the most powerful OPCPA systems on the market and how Class 5 Photonics pushes lasers to extreme wavelengths at extreme average power. A clear mission to change industry and to provide ground breaking technology to enable researchers to push new limits enhances our success and enabled the company to grow to now 11 employees. Robert gives deep insights about how to grow a former research group to an effective small company, struggles and our deep motivation to contribute in the exciting ultrafast research field. Thanks EPIC for this great interview! You are coming to DESY Photon Science and European XFEL Users' Meeting 29-31 January 2020?
We are exhibiting on Friday at booth K11 and are looking forward to explain you our latest news from our high power OPCPA systems. Also, don't miss our poster about the SUPERNOVA OPCPA with up to 100 W average power at 800 nm, 1550 nm and 2 µm. Merry Christmas and a happy new year wishes the Class 5 Photonics Team. It was an exciting year 2019 with many diverse and interesting projects. We built and installed laser systems for a vast scientific community from multi-photon microscopy, ultra-fast material science to attosecond science covering products from 5 W to 100 W average power. Our team grew by four more employees to support our deep expertise in laser science and ultrafast applications as well as sales and marketing. We look forward to new challenges and new exciting projects in 2020 to serve the ultrafast scientific community!  We congratulate Thorlabs to the acquisition of OPA technology for 2- and 3-photon-microscopy from KMLabs. This clearly shows the strategic importance of this rising field of research. At Class 5 Photonics, we are contributing to this field with award-winning high-power laser technology, enabling novel fast volumetric neuronal imaging techniques.
Within our partnership with Coherent (Santa Clara), we offer and have sold the White Dwarf OPCPA at imaging wavelengths of 960, 1300 and 1700 nm (multi-output) and as few-cycle versions at 800 nm and 2000 nm (multi-output) with µJ pulse energies at record repetition rates up to 10 MHz and unprecedented pulse-to-pulse-stability and reliability. Owing to their high second-order nonlinear susceptibility, organic crystals have gained tremendous interest as THz generators within the scientific community. Recently, high-field THz generation in several organic crystals have been demonstrated by various research groups. The velocity phase matching condition is achieved using collinear propagating geometry. The phase matching condition is best fullfilled when the pump wavelength is in the IR range from 1400 nm to 1700 nm. The absorption of the pump light in the crystals is reduced in this wavelength region, leading to an increased damage threshold, which enables higher pump fluences and hence a higher conversion efficiency.
Our compact and versatile White Dwarf HE laser system is extended to a tunable, high power version centered at a wavelength of 1.55 µm with a pulse duration of < 36 fs making it an optimal source for THz generation with organic crystals. In addition, an optically synchronized compressed probe pulse with a pulse duration of < 15 fs at 850 nm is available as a second output channel. The White Dwarf HE is available with 10, 20 or 30 W output power. We are already looking forward to Photonics West 2020 in San Francisco!! As usual, we can be found in the German Pavillon together with a lot of other innovative, young companies. Meet us there at booth number 4545-40 and we show you our latest developments and updates of our powerful OPCPA systems. Also we are excited to be sponsor of the Ultrafast Phenomena and Nanophotonics session. The latest scientific results about ultra-fast material science, THz spectroscopy, plasmonics and nanophotonics will be shown and discussed here. We are honored to present results about our "Femtosecond OPCPAs from UV to short-wave-IR wavelengths for ultrafast dynamics experiments from condensed matter to atoms, molecules, and clusters" in the Ultrafast Optical Techniques session lead by Giulio N. Cerullo. Don't miss it! UPDATE - our scientific talks:
 Class 5 Photonics is a Silver sponsor at Ultrafast Optics XII, which will be held October 6–11, 2019 in Bol on the Island of Brač, Croatia.
We will present a poster and a commercial talk on Monday evening about our 100 W-level Supernova OPCPA providing extreme average powers and outstanding performance combined with stable operation. Also don't miss the talk on Monday 5 pm about "High power, 100 kHz repetition rate OPCPA operating at 800 nm and 1.5 – 2.0 µm" from staff scientist at SLAC!
Additionally, the White Dwarf OPCPA can be configured for three-photon excitation of red fluorescent proteins at 1700 nm. Pulse energies of more than 2 µJ at 1 MHz repetition rate allow fast imaging of deep-tissue.
The White Dwarf OPCPA implements the Coherent Monaco industrial fiber laser as pump source for long-term stability, reliability and turn-key operation. |
