Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference最新文献

{"title":"Novel AMP surface treatment for improving optical fiber strength and laser gain (Conference Presentation)","authors":"D. VanBlarcom, D. Drachenberg, M. Monticelli, G. Davalos, S. Davis, N. Schenkel, M. Cook, R. Crist, M. Messerly, J. Dawson","doi":"10.1117/12.2501563","DOIUrl":"https://doi.org/10.1117/12.2501563","url":null,"abstract":"Contaminants can severely limit the efficiency, laser damage threshold, and strength of photonic crystal fiber-based lasers. Such contamination can occur due to environmental exposure during the pulling or stacking of rods and tubes or improper handling and storage of these glass components. A preform made by the “stack and draw” process is susceptible to incorporating surface contaminants into the bulk laser glass. \u0000We have adapted cleaning and handling protocols originally developed for processing large fused silica optics for the National Ignition Facility. The etch cleaning process reported here mimics the “AMP” or “Advanced Mitigation Process” developed for NIF optics that see high fluence 351nm light. In addition, all cleaning, fixturing and assembly processes used to prep a stack for pulling into a fiber are done in a Class 100 cleanroom. Glass rods (1-3mm in diameter and 10” long) are assembled into a Teflon fixture that only contacts the rods at each end. The loaded fixture receives 120kHz ultrasonic cleaning in 10% sodium hydroxide at 45C and 3% Brulin 1696 detergent at 55C. Parts are thoroughly rinsed using ultrasonicated ultrapure water and spray rinses. A 200nm etch in buffered hydrofluoric acid (6:1 BOE diluted 2:1 in DI water) is followed by additional ultasonicated (120kHz-270kHz) ultrapure water and spray rinse. Finally, the components are allowed to fully dry inside the Teflon frame. The rods are cleaned, stacked, and assembled into a fused silica tube.\u0000The preform stack is then returned to a non-cleanroom area to be pulled into fiber using standard telecom fiber-based draw tower equipment and without clean air filters around the draw area. Four fibers were made to test independently the damage threshold and the background loss, two Yb core active fibers and two silica core (F clad) fibers. One of each was cleaned with the AMP process, and one of each with a methanol wipe cleaning process. The active fiber was coated with a dual acrylate coating, first with a low-index inner coating to provide a pump cladding, and then with a relatively hard coating to protect the relatively soft primary coating. The active fibers were pumped at 980nm in a double Fresnel cavity configuration and the power increased until the fiber was damaged up to 1kW. The passive fiber background loss was measured using a standard cut-back technique. Replacing the former methanol wipe clean process with this aqueous cleaning process improved the 1060nm damage threshold of a fiber laser by >30x to above the kW level in the laboratory and reduced the background attenuation by >18x. Early indications are that the acid etching also makes the tensile strength of the fiber consistently high. \u0000\u0000This work was performed under the auspices of the U.S. Department of Energy by Lawrence\u0000Livermore National Laboratory under Contract DE-AC52-07NA27344.","PeriodicalId":374450,"journal":{"name":"Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130933385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser damage of Yb:YAG active mirrors under atmospheric, vacuum, and cryogenic conditions (Conference Presentation)","authors":"Hanchen Wang, A. Meadows, E. Jankowska, B. Reagan, J. Rocca, C. Menoni","doi":"10.1117/12.2501564","DOIUrl":"https://doi.org/10.1117/12.2501564","url":null,"abstract":"The demonstration of a Yb:YAG chirped pulse amplification laser producing 1 J, 5 ps pulses at 500 Hz repetition rate [1] and recently 1 J pulses at 1 kHz repetition rate [2] relied on efficient thermal management and high performance multilayer dielectric coatings on the laser amplifier active mirrors. In the active mirror configuration, the Yb:YAG amplifier crystals use HfO2/SiO2 multilayer dielectric anti-reflection (AR) and high reflection (HR) coatings. The Joule-level amplifier is operated in vacuum and at liquid nitrogen boiling temperature (77 K) with 1030 nm, 220 ps duration laser pulses making four reflections from each HR coating and 8 passes through each AR coating. The LIDT performance of these coatings is crucial to the future scaling of these amplifiers.\u0000\u0000In this work we describe results of an investigation of the laser induced damage threshold (LIDT) of Yb:YAG active mirror laser amplifier disks at atmospheric, vacuum and cryogenic temperature conditions. The measurements were conducted for 220 ps pulses, the typical pulse duration of stretched pulses we are using to implement kW-class average power CPA laser amplifiers [1,2]. We measured the 1-on-1 (single-shot) and 3000-on-1 LIDT on Yb:YAG crystals with and without the coatings. The results show that the LIDT for single shot damage occurs near 20 J/cm2, and 100% damage probability occurs near 29 J/cm2 for either the uncoated or coated Yb:YAG crystal at atmospheric conditions. Similar results were obtained in the vacuum and cryogenic temperatures tests. This leads to the conclusion that the Yb:YAG material itself, and not the coatings, is the limiting factor in the LIDT. \u0000This work was performed under the auspices of the U.S. Department of Energy, Office of High Energy Physics, Accelerator Stewardship Program under Award DE-SC0016136.\u0000\u0000References\u0000[1] C. Baumgarten, M. Pedicone, H. Bravo, H. Wang, L. Yin, C. S. Menoni, J. J. Rocca, and B. A. Reagan, Optics Letters 41, 3339 (2016).\u0000[2] Brendan A Reagan, Cory Baumgarten, Elzbieta Jankowska, Han Chi, Herman Bravo, Kristian Dehne, Michael Pedicone, Liang Yin, Hanchen Wang, Carmen S Menoni, Jorge J Rocca, High Power Laser Science and Engineering 6, e11 (2018).","PeriodicalId":374450,"journal":{"name":"Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123812333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trends Observed in Ten Years of the BDS Thin Film Laser Damage Competition (Conference Presentation)","authors":"C. Stolz, R. Negres","doi":"10.1117/12.2501954","DOIUrl":"https://doi.org/10.1117/12.2501954","url":null,"abstract":"The thin film damage competition series at the Boulder Damage Symposium provides an opportunity to observe general trends in laser damage behavior between different coating types (high reflector, anti-reflector, Polarizer, and Fabry-Perot filter), wavelength ranges (193 – 1064 nm), and pulse length ranges (40 fs – 18 ns). Additionally, the impact of deposition process, coating material, cleaning process, and layer count can be studied within a single year or more broadly across the history of this competition. Although there are instances where participants attempted to isolate a single variable to better understand it’s impact on laser resistance, this series of competitions isolates the variable of the damage testing service and protocol for a wide variety of participants. In total 275 samples from 58 different participants have been tested at four different laser damage testing facilities over the last ten years. Hafnia was clearly the best high refractive index material except for UV applications; although a wide range of high refractive index materials performed well. The best deposition process varied significantly between the different competitions, so it was much more strongly dependent on the coating type, wavelength, and pulse duration. For 1064 nm coatings with nanosecond scale pulse lengths, e-beam coatings tended to be the best performers. For short pulse length NIR mirrors and nanosecond pulse length UV mirrors, densified coating processes which all involved sputtering of the target material were the best performers. For UV AR coatings and excimer mirrors, both tested at nanosecond pulse lengths, they tended to favor very low energetic deposition methods yielding soft coatings such as sol gel dip coating for the AR and resistive heating of fluorides for the excimer mirrors. Finally cleaning method and layer count have had a less obvious correlation with laser resistance over the history of this thin film damage competition.","PeriodicalId":374450,"journal":{"name":"Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121735179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"U.S. National Committee proposed revision to the ISO Laser Damage Standard: 2018 Progress Report (Conference Presentation)","authors":"J. Arenberg, D. Howland, Michael D. Thomas, Trey Turner, A. Krisiloff","doi":"10.1117/12.2500369","DOIUrl":"https://doi.org/10.1117/12.2500369","url":null,"abstract":"","PeriodicalId":374450,"journal":{"name":"Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129231830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser-induced damage measurements of crystalline coatings (Conference Presentation)","authors":"G. Cole, D. Follman, P. Heu, G. Truong, C. Deutsch, C. Franz, A. Alexandrovski, Bin Ma, Xinbin Cheng","doi":"10.1117/12.2326769","DOIUrl":"https://doi.org/10.1117/12.2326769","url":null,"abstract":"Substrate-transferred crystalline coatings have emerged as a groundbreaking new concept in optical interference coatings. Building upon our initial demonstration of this technology in 2013, we have recently realized significant improvements in the optical performance of these novel single-crystal GaAs/AlGaAs multilayers. In the near-infrared, for center wavelengths spanning 1064 to 1560 nm, we have reduced the excess optical losses (scatter + absorption) to less than 5 ppm, with the direct measurement of sub-ppm optical absorption in these films, enabling the realization of a cavity finesse exceeding 600,000 at the telecom-relevant wavelength range near 1550 nm. In this presentation we outline preliminary measurements of the laser-induced damage threshold (LIDT) of these novel semiconductor-based interference coatings. For pulsed excitation (ns pulse durations at 1064 nm), the narrow bandgap of the constituent mirror materials limits the LIDT to 3-5 J/cm2. Under these conditions, laser damage is driven by two-photon absorption (TPA) in the semiconductor multilayer, primarily the high-refractive-index GaAs films. Note that improved performance may be realized for illumination wavelengths >1740 nm, where TPA is eliminated. For continuous-wave (CW) illumination, the high thermal conductivity (~30 Wm-1K-1) and low intrinsic absorption yield the potential for excellent performance. Here we present preliminary CW damage measurements for a 10-ppm transmission quarter-wave GaAs/AlGaAs Bragg mirror transferred to super-polished fused silica, with only a 1.4 K temperature rise for an intensity of ~1.5 MW/cm2. Further efforts will continue to push the limits of the structure with the aim of determining the maximum CW intensity that such mirrors can tolerate.","PeriodicalId":374450,"journal":{"name":"Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126247650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of adaptively mixed thin film (AMTF) deposited by a dielectric material and a plastic (Conference Presentation)","authors":"K. Yoshida, T. Okamoto, T. Mikami, H. Yoshida, J. Kawanaka, N. Miyanaga, S. Motokoshi, T. Jitsuno","doi":"10.1117/12.2500273","DOIUrl":"https://doi.org/10.1117/12.2500273","url":null,"abstract":"","PeriodicalId":374450,"journal":{"name":"Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134116206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Test Methods for Laser-induced Damage Threshold of Medical Laser Delivery and Applications Systems (Conference Presentation)","authors":"H. Berlien","doi":"10.1117/12.2502570","DOIUrl":"https://doi.org/10.1117/12.2502570","url":null,"abstract":"Fire in an operating room is the most dangerous situation for patient and staff. Besides electrosurgical devices and endoscopic light sources, even surgical lasers can be ignition sources for drapes, gowns and tracheal tubes. This risk was identified very early and several ISO standards for laser proof materials have been published. The medical beam delivery system itself, however, was out of focus. Due to the increasing market on the one hand and necessity for cost reduction in health care on the other hand fibres have come into the market with a risk of self-ignition of the core or cladding material. Furthermore with reinvention of fibre-applicator-systems for contact application or integrated diffusor systems they have an increased risk for self-ignition due to high absorption. So it is important to perform quality requirements for companies suppliers and hospitals. At this time there is no existing work or standard to this topic. This project elaborates reproducible test parameters for medical beam delivery systems. \u0000Because the problem of ignition and damage due to laser transmission is not limited only to medical devices but even e.g. in communication systems and fiber laser system the work was started in close cooperation with WG1 SC9 to avoid any duplication. The presented draft follows the structure, terminology and test procedure the existing standards for surgical drapes ISO11810 and Endotracheal tubes ISO11990 to avoid inconsistency in these standards","PeriodicalId":374450,"journal":{"name":"Laser-Induced Damage in Optical Materials 2018: 50th Anniversary Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116959115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}