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Orlando, FL, United States

Hemmer M.,ICFO - Institute of Photonic Sciences | Sanchez D.,ICFO - Institute of Photonic Sciences | Jelinek M.,Czech Technical University | Smirnov V.,OptiGrate Corporation | And 4 more authors.
Optics Letters | Year: 2015

A 2-μm wavelength laser delivering up to 39-mJ energy, 10 ps duration pulses at 100-Hz repetition rate is reported. The system relies on chirped pulse amplification (CPA): a modelocked Er:Tm:Ho fiber-seeder is followed by a Ho:YLF-based regenerative amplifier and a cryogenically cooled Ho:YLF single pass amplifier. Stretching and compressing are performed with large aperture chirped volume Bragg gratings (CVBG). At a peak power of 3.3 GW, the stability was <1% rms over 1 h, confirming high suitability for OPCPA and extreme nonlinear optics applications. © 2015 Optical Society of America. Source

OptiGrate Corporation and University of Central Florida | Date: 2012-02-10

A method for two-dimensional spatial (transverse) mode selection in waveguide and free-space laser resonators and associated laser systems employing said resonators. The invention is based on the cylindrical symmetry of the angular selectivity of reflecting volume Bragg gratings (R-VBGs) that are used as spectrally selective minors in resonators. Matching the divergence of a laser beam and the angular selectivity a reflecting volume Bragg grating can establish different losses for transverse modes of different orders, while not restricting the aperture of the laser resonator, and enables single mode operation for resonators that support a plurality of transverse modes. The invention provides a laser having increased brightness without a decrease of efficiency.

Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 749.99K | Year: 2012

The objective of this proposal is to extend the technology of chirped pulse amplification in ultrashort pulse lasers based on chirped volume Bragg gratings (CBGs) to higher stretching/ compression ratio and make the device more robust. In Phase I OptiGrate demonstrated high quality stretching and compression by CBGs fabricated in photo-thermo-refractive (PTR) glass. Phase II research and development enabled reliable manufacturing of CBGs designed for ultrashort pulse laser systems and extended the stretching time to the unprecedented level of 1 ns while this pulse could be compressed to the level of 200 fs. Record average power of 200 W has been demonstrated. The benefits of usage of such gratings are based on a compact geometry, unprecedented stability to optical radiation, high diffraction efficiency, absence of polarization dependence and durability to environmental conditions. However the most strategic importance of this technology is its scalability to large apertures and thickness which enable scaling to higher power and longer stretching. The specific target set for Phase II.5 of this project is a demonstration of multipass CBGs where 2-ns stretching time which is combined with large aperture up to 1010 mm capable of compressing pulses with energies more than 20 mJ.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2014

The laser sources emitting from short to long infrared wavelengths are used for environmental sensing, metrology and clinical diagnosis, LADAR applications. The second atmospheric window between 3-5 um is crucial where a large number of gases, e.g. methane, nitric oxide, carbon mono-dioxide or formaldehyde, can be detected. Due to the presence of very strong fundamental stretching modes of O-H, C-H and N-H bonds that are up to orders of magnitude stronger than the overtones in the near-IR, detection limits down to sub-ppb concentrations can be obtained. One of the necessary components for such measurements is optical isolator. However, there are no commercially available devices for this spectral range. The main objective of the current proposal is to create an optical isolator for 3-5 um that could be used in laser applications. The technical approach is to develop a vitreous material that is transparent in mid IR spectral region and can accept high concentration of ions that increase magnetooptical constant. Dependence of magnetooptical sensitivity on different dopants will be studied, a technology of fabrication of mid IR transparent magnetooptical glass will be developed and optical isolation in 3-5 um region will be demonstrated in bulk and fiber geometries.

Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase I | Award Amount: 99.00K | Year: 2011

The proposed innovation is based on a combination of two new technologies developed at the Center for Laser Technology at the Fraunhofer Institute and OptiGrate Corp. and aims to integrate advanced packaging of single emitter laser diodes, spectral and angular narrowing of these diodes by volume Bragg gratings in external resonators, and spectral combining of laser beams by a stack of volume Bragg gratings, all in a robust compact laser module. The use of individual laser diodes instead of diode bars ensures high reliability and very high brightness of the combined of output power from many single emitters without the need for beam transformation. By spectrally combining several high power modules that have been locked to a very narrow linewidth our approach will result in a dramatic increase of the spectral and spatial brightness of these laser modules compared to conventional diode bars. Efficient spectral combining of beams from several modules with no penalty in power will result in a spectrum narrower than that from any conventional high power laser bar. The brightness of the proposed device will be about 1 order of magnitude higher than the current state of the art and will facilitate a 5 kW pumping source coupled to 100 um 0.22 NA fiber.

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