{"title":"A wide bandwidth THz emission based on two color chirped laser plasma interaction","authors":"masood saeed, A. Khorsandi","doi":"10.1364/optcon.497701","DOIUrl":"https://doi.org/10.1364/optcon.497701","url":null,"abstract":"","PeriodicalId":74366,"journal":{"name":"Optics continuum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41804576","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}
R. Darthy, C. Venkateswaran, L R Amruth Kumar, Yogesh Natesan
{"title":"Engineerable Wavevector Diagrams of Non-Moiré Geometry-Based Photonic Crystals for Beam Steering Applications","authors":"R. Darthy, C. Venkateswaran, L R Amruth Kumar, Yogesh Natesan","doi":"10.1364/optcon.495651","DOIUrl":"https://doi.org/10.1364/optcon.495651","url":null,"abstract":"","PeriodicalId":74366,"journal":{"name":"Optics continuum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44487320","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}
High power laser ablation can lead to the creation of plasma and the emission of bright light, which can prevent the direct observation of the workpiece. Alternative techniques for enabling the visualization of the sample during laser machining are therefore of interest. Here, we show that the plasma created during laser ablation, when viewed perpendicular to the sample surface, contains information regarding the appearance of the sample. Specifically, we show that deep learning can predict the 2D appearance of the sample, directly from 2D projected images of the plasma produced during single pulse femtosecond laser ablation. In addition, this approach also enables the identification of the pulse energy of the most recent laser pulse used to machine the sample. This work could have applications across laser materials processing in research and industry, in cases where there is a requirement for real-time visualization of the sample surface during laser ablation.
{"title":"Visualizing laser ablation using plasma imaging and deep learning","authors":"J. Grant-Jacob, B. Mills, M. Zervas","doi":"10.1364/optcon.495923","DOIUrl":"https://doi.org/10.1364/optcon.495923","url":null,"abstract":"High power laser ablation can lead to the creation of plasma and the emission of bright light, which can prevent the direct observation of the workpiece. Alternative techniques for enabling the visualization of the sample during laser machining are therefore of interest. Here, we show that the plasma created during laser ablation, when viewed perpendicular to the sample surface, contains information regarding the appearance of the sample. Specifically, we show that deep learning can predict the 2D appearance of the sample, directly from 2D projected images of the plasma produced during single pulse femtosecond laser ablation. In addition, this approach also enables the identification of the pulse energy of the most recent laser pulse used to machine the sample. This work could have applications across laser materials processing in research and industry, in cases where there is a requirement for real-time visualization of the sample surface during laser ablation.","PeriodicalId":74366,"journal":{"name":"Optics continuum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43785352","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}
C. Ooi, K. Lim, K. Ng, W. Chong, S. Gan, B. Goh, H. Ahmad
This article reports the spectral properties of a Ge2Sb2Se4Te1 (GSST) -coated tilted fiber Bragg grating to the changes of surrounding refractive index (SRI). The variations of the cladding mode resonance amplitudes and wavelengths under two orthogonal polarization modes are analyzed and validated with the simulation results. The introduction of the high index coating has induced non-degeneracy to the cladding modes, but the effect gradually diminishes with increasing SRI. The SRI sensitivities of the s-polarized modes have been substantially suppressed and became 20 times lower than that of p-polarized modes. The findings also reveal the association between the cladding resonance amplitudes, the imaginary part of the effective refractive indices and the evanescent field intensity distributions.
{"title":"Spectral responses of tilted fiber Bragg grating coated with a thin Ge2Sb2Se4Te1 layer","authors":"C. Ooi, K. Lim, K. Ng, W. Chong, S. Gan, B. Goh, H. Ahmad","doi":"10.1364/optcon.492830","DOIUrl":"https://doi.org/10.1364/optcon.492830","url":null,"abstract":"This article reports the spectral properties of a Ge2Sb2Se4Te1 (GSST) -coated tilted fiber Bragg grating to the changes of surrounding refractive index (SRI). The variations of the cladding mode resonance amplitudes and wavelengths under two orthogonal polarization modes are analyzed and validated with the simulation results. The introduction of the high index coating has induced non-degeneracy to the cladding modes, but the effect gradually diminishes with increasing SRI. The SRI sensitivities of the s-polarized modes have been substantially suppressed and became 20 times lower than that of p-polarized modes. The findings also reveal the association between the cladding resonance amplitudes, the imaginary part of the effective refractive indices and the evanescent field intensity distributions.","PeriodicalId":74366,"journal":{"name":"Optics continuum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42322766","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":"Focusing characteristic Change and Processing Characteristic Evaluation of Femtosecond-to-Picosecond Pulse Lasers Above Air Ionization Threshold","authors":"Itsuki Nishibata, N. Nakanii, T. Sano","doi":"10.1364/optcon.496411","DOIUrl":"https://doi.org/10.1364/optcon.496411","url":null,"abstract":"","PeriodicalId":74366,"journal":{"name":"Optics continuum","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48823111","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}
Bessel beams have found important applications due to their propagation invariant nature. However, the presence of sidelobes has proven a hindrance in key imaging and biophotonics applications. We describe the design and generation of sidelobe-suppressed Bessel-like beams (SSBB) that provide enhanced contrast for light-sheet imaging. The sidelobe suppression is achieved by the interference of two Bessel beams with slightly different wavevectors. Axicon phase functions for each Bessel beam are combined into a single phase function using the random multiplexing technique. This phase function is realised using a spatial light modulator to generate a SSBB. The generated beam at 633 nm has a 1/ e 2 radius of 44 µm and a propagation invariant distance of 39 mm which is more than four times that of the Rayleigh range of a Gaussian beam with the same 1/ e 2 radius. Within this distance, the overall peak intensity of the sidelobes of the SSBB is less than 10% that of the main lobe peak intensity. In addition, through numerical simulation for the recovery of spatial frequencies, we show that the SSBB improves image contrast compared to a Bessel beam for light-sheet imaging. We also show that the designed phase function can be realised using a meta-optical element.
{"title":"Generation of Bessel-like beams with reduced sidelobes for enhanced light-sheet microscopy","authors":"Jerin George, Kishan Dholakia, Shanti Bhattacharya","doi":"10.1364/optcon.493003","DOIUrl":"https://doi.org/10.1364/optcon.493003","url":null,"abstract":"Bessel beams have found important applications due to their propagation invariant nature. However, the presence of sidelobes has proven a hindrance in key imaging and biophotonics applications. We describe the design and generation of sidelobe-suppressed Bessel-like beams (SSBB) that provide enhanced contrast for light-sheet imaging. The sidelobe suppression is achieved by the interference of two Bessel beams with slightly different wavevectors. Axicon phase functions for each Bessel beam are combined into a single phase function using the random multiplexing technique. This phase function is realised using a spatial light modulator to generate a SSBB. The generated beam at 633 nm has a 1/ e 2 radius of 44 µm and a propagation invariant distance of 39 mm which is more than four times that of the Rayleigh range of a Gaussian beam with the same 1/ e 2 radius. Within this distance, the overall peak intensity of the sidelobes of the SSBB is less than 10% that of the main lobe peak intensity. In addition, through numerical simulation for the recovery of spatial frequencies, we show that the SSBB improves image contrast compared to a Bessel beam for light-sheet imaging. We also show that the designed phase function can be realised using a meta-optical element.","PeriodicalId":74366,"journal":{"name":"Optics continuum","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135857727","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：