{"title":"等离子体烫伤反射镜散射诱导的下游光束调制","authors":"J. Schmidt, M. Runkel, K. E. Martin, C. Stolz","doi":"10.1117/12.748446","DOIUrl":null,"url":null,"abstract":"Previous work concluded that plasma scalds on laser-conditioned multilayer dielectric mirror coatings are a stable, benign damage morphology. Recent large-aperture measurements indicate that plasma scalds may lead to fratricide of down-stream optics by increasing beam contrast. This paper describes the results of measurements performed to examine the effect of quasi-periodic plasma scalds covering the entire clear aperture on downstream beam modulation. A collimated, linearly-polarized 1053-nm beamline was constructed that irradiated approximately 5 cm2 of the plasma scalded region. This beam was propagated ~8 meters and sampled with a 10-bit, megapixel CCD camera and analyzed for contrast (peak/average intensity). A lineout across the sample was built up by translating the optic across the beam. The contrast results were compared to a baseline wedged flat with surface figure of λ/100 and a contrast adder for the plasma scalds calculated. This was defined by. In all, optics with average plasma scald fractions of 0.9, 2.3, 4 and 14% were measured. Preliminary results indicate that plasma scald fractions of 4% and below contribute a contrast adder of less than 2.5%.","PeriodicalId":204978,"journal":{"name":"SPIE Laser Damage","volume":"38 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2007-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"10","resultStr":"{\"title\":\"Scattering-induced downstream beam modulation by plasma scalded mirrors\",\"authors\":\"J. Schmidt, M. Runkel, K. E. Martin, C. Stolz\",\"doi\":\"10.1117/12.748446\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Previous work concluded that plasma scalds on laser-conditioned multilayer dielectric mirror coatings are a stable, benign damage morphology. Recent large-aperture measurements indicate that plasma scalds may lead to fratricide of down-stream optics by increasing beam contrast. This paper describes the results of measurements performed to examine the effect of quasi-periodic plasma scalds covering the entire clear aperture on downstream beam modulation. A collimated, linearly-polarized 1053-nm beamline was constructed that irradiated approximately 5 cm2 of the plasma scalded region. This beam was propagated ~8 meters and sampled with a 10-bit, megapixel CCD camera and analyzed for contrast (peak/average intensity). A lineout across the sample was built up by translating the optic across the beam. The contrast results were compared to a baseline wedged flat with surface figure of λ/100 and a contrast adder for the plasma scalds calculated. This was defined by. In all, optics with average plasma scald fractions of 0.9, 2.3, 4 and 14% were measured. Preliminary results indicate that plasma scald fractions of 4% and below contribute a contrast adder of less than 2.5%.\",\"PeriodicalId\":204978,\"journal\":{\"name\":\"SPIE Laser Damage\",\"volume\":\"38 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2007-10-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"10\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"SPIE Laser Damage\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1117/12.748446\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"SPIE Laser Damage","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1117/12.748446","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Scattering-induced downstream beam modulation by plasma scalded mirrors
Previous work concluded that plasma scalds on laser-conditioned multilayer dielectric mirror coatings are a stable, benign damage morphology. Recent large-aperture measurements indicate that plasma scalds may lead to fratricide of down-stream optics by increasing beam contrast. This paper describes the results of measurements performed to examine the effect of quasi-periodic plasma scalds covering the entire clear aperture on downstream beam modulation. A collimated, linearly-polarized 1053-nm beamline was constructed that irradiated approximately 5 cm2 of the plasma scalded region. This beam was propagated ~8 meters and sampled with a 10-bit, megapixel CCD camera and analyzed for contrast (peak/average intensity). A lineout across the sample was built up by translating the optic across the beam. The contrast results were compared to a baseline wedged flat with surface figure of λ/100 and a contrast adder for the plasma scalds calculated. This was defined by. In all, optics with average plasma scald fractions of 0.9, 2.3, 4 and 14% were measured. Preliminary results indicate that plasma scald fractions of 4% and below contribute a contrast adder of less than 2.5%.