L. Blanco, Marie Blavier, M. Glanc, F. Pouplard, S. Tick, I. Maksimovic, G. Chenegros, L. Mugnier, F. Lacombe, G. Rousset, M. Pâques, J. Le Gargasson, J. Sahel
{"title":"First steps toward 3D high resolution imaging using adaptive optics and full-field optical coherence tomography","authors":"L. Blanco, Marie Blavier, M. Glanc, F. Pouplard, S. Tick, I. Maksimovic, G. Chenegros, L. Mugnier, F. Lacombe, G. Rousset, M. Pâques, J. Le Gargasson, J. Sahel","doi":"10.1117/12.812225","DOIUrl":"https://doi.org/10.1117/12.812225","url":null,"abstract":"We describe here two parts of our future 3D fundus camera coupling Adaptive Optics and full-field Optical Coherence Tomography. The first part is an Adaptive Optics flood imager installed at the Quinze-Vingts Hospital, regularly used on healthy and pathological eyes. A posteriori image reconstruction is performed, increasing the final image quality and field of view. The instrument lateral resolution is better than 2 microns. The second part is a full-field Optical Coherence Tomograph, which has demonstrated capability of performing a simple kind of \"4 phases\" image reconstruction of non biological samples and ex situ retinas. Final aim is to couple both parts in order to achieve 3D high resolution mapping of in vivo retinas.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125172669","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}
A. Freitas, Maria Valeria Robes Velasco, Marcus Paulo Raele, T. M. Kaneko, N. Vieira, A. Baby
{"title":"Structural characterization of hair fiber by optical coherence tomography (OCT)","authors":"A. Freitas, Maria Valeria Robes Velasco, Marcus Paulo Raele, T. M. Kaneko, N. Vieira, A. Baby","doi":"10.1117/12.814948","DOIUrl":"https://doi.org/10.1117/12.814948","url":null,"abstract":"In this work we use the optical coherence tomography (OCT) technique to produce in vitro transversal section images of human hair. It was possible to identify in the A-scan protocol its principal structures: cuticle, cortex and medulla. The mean diameter of medulla was 29 ± 7 μm and hair diameter was 122 ± 16 μm in our samples of standard Afro-ethnic hair. We also compared the OCT signal before and after chemical treatment with 18% w/w ammonium thioglycolate solution. After chemical treatment, it was not possible to identify the main structures of hair fiber, due the index matching promoted by deleterious action of chemical agent. A tridimensional image was built starting from 601 cross-sectional images (slices). Each slice was taken in steps of 6.0 μm at 8 frames per second, and the whole 3D image was built in 60 seconds.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124040883","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}
L. Neagu, A. L. Lobo Ribeiro, R. Cucu, A. Bradu, Lisha Ma, A. Podoleanu
{"title":"En-face OCT system at 1060 nm","authors":"L. Neagu, A. L. Lobo Ribeiro, R. Cucu, A. Bradu, Lisha Ma, A. Podoleanu","doi":"10.1117/12.822500","DOIUrl":"https://doi.org/10.1117/12.822500","url":null,"abstract":"A highly efficient power optical coherence tomography configuration is implemented using a Multiwave Photonics broadband source centred at 1060 nm wavelength, FWHM = 50 nm and a Mach Zehnder interferometer. The interferometer contains a fibre acousto-optic modulator in each arm. One is driven at a fixed frequency of 40 MHz while the other via an RF Function Generation. In this way, the en-face OCT signal is modulated on a carrier frequency adjustable in the range 0 kHz to 1.5 MHz. A circulator is placed in the sample arm. Light retroreflected from the sample is sent via the circulator to a balanced coupler where it interferes with the reference beam. A translation stage is used in the reference arm to adjust the optical path difference in the interferometer. The result is photodetected using two InGaAs photodetectors followed by a differential amplifier in a balance detection configuration The system has been used to acquire en-face images as well as cross section optical coherence tomography images from skin and embryos based on T-scans (transversal reflectivity profiles).","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134411131","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}
A. Tumlinson, B. Hermann, T. Margrain, B. Hofer, B. Povazay, W. Drexler
{"title":"Retinal intrinsic optical signal and optical coherence tomography","authors":"A. Tumlinson, B. Hermann, T. Margrain, B. Hofer, B. Povazay, W. Drexler","doi":"10.1117/12.819401","DOIUrl":"https://doi.org/10.1117/12.819401","url":null,"abstract":"The amount of light backscattered from neural tissues changes as a function of activation and is the basis of intrinsic optical signal (IOS). Typically IOS is observed by looking at darkfield scatter with a CCD camera. The retina is a calculating portion of the central nervous grey matter with an optical quality window, and is likewise easily stimulated optically. Therefore the retina makes a natural model for observing neural interactions with optical tools. Optical coherence tomography (OCT) is an imaging modality that provides depth resolved maps of the amount of light backscattered from tissue that has wide clinical use for observing structural defects associated with ophthalmic disease. It is therefore also natural to use OCT as means to observe intrinsic optical signal in the retina. Indeed, OCT has recently been used to observe an increase in backscatter at the level of the outer photoreceptor segment after bleaching light stimulation in an excised rabbit retina. We are currently attempting to translate this result towards a diagnostic technique for photoreceptor dysfunction in human patients. Currently patient motion and physiological noise present barriers that must be overcome with increases in technological and experimental sophistication. This proceeding reviews current understanding of retinal intrinsic optical signal and discusses its measurement challenge.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122152716","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}
Bhanu Rakesh Penmetsa, M. Khandwala, A. Bradu, M. Hughes, Carole A. Jones, J. Schofield, A. Podoleanu
{"title":"Imaging of basal cell carcinoma tissue using en-face OCT","authors":"Bhanu Rakesh Penmetsa, M. Khandwala, A. Bradu, M. Hughes, Carole A. Jones, J. Schofield, A. Podoleanu","doi":"10.1117/12.821410","DOIUrl":"https://doi.org/10.1117/12.821410","url":null,"abstract":"We have investigated the applicability of en-face OCT in imaging freshly excised biopsies of Basal Cell Carcinoma. Encouraging results have been obtained in identifying tumor features and abnormal skin architecture.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130517801","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":"Optical fiber sources for measurement and imaging","authors":"A. L. Lobo Ribeiro, M. Melo, J. Salcedo","doi":"10.1117/12.808056","DOIUrl":"https://doi.org/10.1117/12.808056","url":null,"abstract":"An overview of the different type of fibre broadband sources and some fiber laser sources that operate as incoherent sources, are briefly discussed and some practical applications are presented. The optical performance and characteristics of several of these fiber sources are reviewed, including emission spectra profiles, autocorrelation functions, wavelength and power stabilities, and polarization behavior.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134565367","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}
Yu. O. Kostin, P. I. Lapin, V. V. Prokhorov, V. R. Shidlovsky, S. Yakubovich
{"title":"Towards 1.0 W CW reliable SLD at 840 nm","authors":"Yu. O. Kostin, P. I. Lapin, V. V. Prokhorov, V. R. Shidlovsky, S. Yakubovich","doi":"10.1117/12.811103","DOIUrl":"https://doi.org/10.1117/12.811103","url":null,"abstract":"The prototypes of high-efficiency SLDs with COD threshold of more than 5•106 W/cm2 were investigated. Single spatial mode samples with 4 μm-wide active channel exhibited CW output power of more than 200 mW. Preliminary reliability tests at 100 mW level were successful. It was shown that in double-pass operation mode achieved using SM fiber reflector, external efficiency can be increased significantly. The estimations show that multimode SLD with 20-30 μm active channel width based on the same QW heterostructure may ensure reliable enough operation at output power level of more than 0.5W.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124868537","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}
J. Rolland, P. Meemon, S. Murali, Apurva Jain, Nicolene Papp, K. P. Thompson, Kye S. Lee
{"title":"Gabor domain optical coherence microscopy","authors":"J. Rolland, P. Meemon, S. Murali, Apurva Jain, Nicolene Papp, K. P. Thompson, Kye S. Lee","doi":"10.1117/12.816930","DOIUrl":"https://doi.org/10.1117/12.816930","url":null,"abstract":"Optical Coherence Microscopy (OCM) is an emerging technology capable of depth sectioning of biological tissue at the micrometer scale. In this paper, we propose a developing technology we call Gabor Domain Optical Coherence Microscopy (GD-OCM), whose innovation is two folds: (1) A high lateral resolution optical design of a dynamic-focusing optical probe with no moving parts, which provides an invariant resolution of currently 3 μm across a 2mm full-field of view and 2mm imaging depth by design; (2) An acquisition scheme (using the probe) that is capable of performing automatic data fusion to render an in-focus high resolution image throughout the depth of sample at in vivo speeds.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133709624","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}
Erika Odlund, M. Navarro, E. Lavergne, Franck Martins, X. Levecq, A. Dubra
{"title":"Optimization of the temporal performance of a deformable mirror for use in ophthalmic applications","authors":"Erika Odlund, M. Navarro, E. Lavergne, Franck Martins, X. Levecq, A. Dubra","doi":"10.1117/12.814906","DOIUrl":"https://doi.org/10.1117/12.814906","url":null,"abstract":"Adaptive optics (AO) is used to correct wavefront aberrations in light in real-time. An AO system is principally made up of three parts; a wavefront measuring device, a correction device, and a control algorithm to compute the residuals between the measured and a reference wavefront. Deformable mirrors (DM) are commonly used as the correction devices in such a system. This paper presents a method to improve a DM's temporal performance by attenuating parasite oscillations of its reflective membrane when applying high-frequency signals to the mirror actuators. The method consists of implementing low-pass filtering into the software driving the mirror. Different filtering functions were studied both when stimulating one single actuator, and when applying voltages to the complete array of actuators. A linear decomposition in 41 substeps showed the best performance for all considered configurations. The obtained results represented an important reduction of the settling time as well as the overshoot of the signal response.","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127467347","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}
M. Pircher, E. Götzinger, B. Baumann, H. Sattmann, C. Hitzenberger
{"title":"Simultaneous SLO/OCT imaging of the human retina in vivo with high speed axial eye motion correction","authors":"M. Pircher, E. Götzinger, B. Baumann, H. Sattmann, C. Hitzenberger","doi":"10.1117/12.814913","DOIUrl":"https://doi.org/10.1117/12.814913","url":null,"abstract":"Transversal scanning (or en-face) optical coherence tomography (TS-OCT) represents an imaging modality that is capable to record high isotropic resolution images of the human retina in vivo. However, axial eye motion still remains a challenging problem of this technique. In this paper we introduce an improved method of our previously published axial eye motion correction technique. To measure accurately the position of the cornea an auxiliary spectral domain partial coherence interferometer (SD-PCI) operating at 1310nm that is integrated into a TS-OCT system is used. The recorded corneal position is used to drive a rapid scanning optical delay line in the reference arm of the TS-OCT system to correct for axial eye motion. Currently, the correction can be performed with a rate of ~1kHz which is approximately 20 times faster than our previous system and practically eliminates axial eye motion artifacts. The TS-OCT instrument is operated with a line scan rate of 8000 transversal lines per second which enables simultaneous scanning laser ophthalmoscope (SLO) and OCT imaging at a frame rate of 40fps (650x200pixels).)","PeriodicalId":184459,"journal":{"name":"Canterbury Workshop and School in Optical Coherence Tomography and Adaptive Optics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127521438","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}