- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
New clinical ultrahigh-resolution SD-OCT using A-scan matching algorithm
摘要： Purpose A new clinical ultrahigh-resolution spectral domain optical coherence tomography (UHR-SD-OCT) system using an original averaging technique named BA-scan matching algorithm^ was developed. The aim of this study was to determine whether our new UHR-SD-OCT system can obtain clearer sectional images of the retina than conventional standard resolution SD-OCT systems (SR-SD-OCT). Methods We recorded horizontal B-scan images of 42 normal eyes using our new UHR-SD-OCT device (Bi-μ, Kowa) and a conventional SR-SD-OCT (Spectralis, Heidelberg). To evaluate the clarity of the interdigitation zone (IZ) subjectively, the integrity of IZ was divided into three types by two raters. To evaluate the clarity of the IZ objectively, a peak height score (PHS) was calculated at five different points of the macula using the longitudinal reflectivity profile. Results The mean (± SD) of the subjective visibility score of the IZ in the UHR-SD-OCT images was 2.64 ± 0.54 which was significantly higher than the 2.46 ± 0.46 in the SR-SD-OCT images (P = 0.02). The PHS was also significantly higher for the UHR-SD-OCT than for the SR-SD-OCT images at all five locations (all P < 0.01). Conclusion The results indicate that the newly developed clinical UHR-SD-OCT instrument using the A-scan matching algorithm can obtain clearer images of the IZ, and they suggest that this device should be clinically useful in detecting finer structural abnormalities of the outer retina.
关键词： Spectral domain,Ultrahigh-resolution,Optical coherence tomography (OCT),Interdigitation zone,Retina
更新于2025-09-23 15:21:21
-
Ultrahigh resolution spectroscopy for dimethyl sulfide at the ??1- and ??8-bands by a distributed feedback interband cascade laser
摘要： The ultrahigh-resolution, air-broadened mid-infrared absorption spectrum of dimethyl sulfide (DMS) was recorded in the spectral region of 2994.17–2999.03 cm?1, where the strong ν1-/ν8-bands are located. Benefitting from the tunable laser absorption spectrometry with a distributed feedback interband cascade laser, the spectral resolution achieved 5.69 × 10?6 cm?1. The recorded spectra of DMS are very close to that in the Pacific Northwest National Laboratory (PNNL) database, however it has a much lower absorbance uncertainty of 0.38%. And the maximum relative difference of the full width at half maximum and the integrated area of spectral peaks between the recorded spectra and the PNNL data are as large as 16.7% and 27.9%, respectively, which could mainly come from the difference of the spectral resolution. The more accurate reference spectrum is hopeful to be applied to absolute measurement and remote sensing for gaseous DMS.
关键词： Tunable laser absorption spectroscopy (TLAS),Dimethyl sulfide (DMS),Ultrahigh-resolution spectrum,Interband cascade laser (ICL),Mid-infrared
更新于2025-09-23 15:19:57
-
Physical similarity of the processes of laser thermochemical recording on thin metal films and modeling the recording of submicron structures
摘要： Laser thermochemical recording is a flexible method for direct writing the binary planar structures (for instance, diffractive optical elements) by a local laser-induced oxidation of thin metal films. Unfortunately, due to excess of influencing parameters, search for regimes of high-resoluted recording could be complicated. The presented article proposes the way to analyze the hard-to-reach regimes of laser recording by modeling them with more convenient regimes (with different geometric and/or thermochemical parameters) based on their physical similarity.
关键词： Thin films,Laser direct writing,Laser thermochemical writing,Ultrahigh resolution,Laser-induced oxidation
更新于2025-09-11 14:15:04