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In this paper, investigation on fiber laser cutting of CFRP was carried out through establishing a multi-physical finite element model and cutting experiment. A multi-physical field model of laser cutting of CFRP was established. Experiments on 1 kW fiber laser cutting of 1 mm CFRP was performed. The relationship between cutting quality (slit width, notch taper, and HAZ width) and laser process parameters such as laser power and cutting speed was investigated. The results show that the transfer of laser energy in CFRP is mainly along the direction of fiber laying, and the heat transfer speed in carbon fiber is much faster than that in resin. The width of the slit, HAZ and the notch taper all increase with the increasing of laser power. However, the width of slit and HAZ decrease as the cutting speed increase and the notch taper increased first and then decreased. When the laser power is 150 W and the cutting speed is 1 m/min, the cutting quality is better.

The High Throughput Virtual Slit (or HTVS) is a new optical technology which can significantly increase the throughput and resolution of a dispersive spectrometer. The HTVS is able to preserve spectrometer etendue, mitigating photon losses normally associated with a slit. Originally implemented in multimode fiber-input spectrometers, HTVS has now been shown to be broadly applicable to a wide variety of spatially scanning hyperspectral imagers and standoff sensors, enhancing their performance and unlocking new application areas. In essence, the anamorphic elements of the HTVS optical system provide a means to decouple the spatial (iFOV) and spectral resolution of nearly any HSI system. In some scenarios, HTVS can be used to achieve better spectral resolution with the same input slit width. Alternatively, the slit can be widened (to increase the collected signal) while maintaining the same spectral resolution. This newfound flexibility in optimizing critical performance parameters not only improves the performance of HSI systems in existing remote sensing contexts, but also opens up numerous new application areas which were previously inaccessible to hyperspectral techniques. This method adds substantial value to existing HSI designs, particularly in applications involving targets with large spatial extent and requiring high spectral resolution (e.g. standoff Raman spectroscopy). We present recent experimental results from our prototype HTVS pushbroom imager and discuss case studies of standoff Raman detection of hazardous materials, passive detection of faint narrowband and monochromatic sources, and optimal disentangling of target spectral signatures from the solar spectrum under daytime illumination.

This paper presents the Espresso Anamorphic pupil Slicer (APSU) implementation. For ESPRESSO that will be installed on ESO’s Very Large Telescope (VLT). In this work we will present the design and trade off for the pupil slicing system introduced in order to increase the resolving power, effectively decreasing slit width. It’s based onto simplified optical component that introduce large anamorphism while keeping low aberrations by means of cylindrical optics. We describe here the trade off between slicing through two adjacent squared doublets and two achromatic prisms. Preliminary integration and procurement is also discussed here.

16th Conference of Novel Optical Systems Design and Optimization, August 26-28, 2013, San Diego, CA, USA, Series: Proceedings of SPIE

Wavelength calibration is important for monochromator and spectrograph before accurate application. In the case of a Czerny-Turner double monochromator, work have been down to find out the relationship between slit widths and wavelength error. We do wavelength calibration in different widths of entrance and exit slits, then get wavelength error. The result shows that different widths of entrance slit and exit slit lead to different wavelength error, and wavelength error can be presented as a function of wavelength and slit widths through curve fitting. Thus, correction can be done by solving this function before accurate measurement.

Bandwidth is an important specification for monochromator and spectrograph. It varies with different slit widths and wavelengths. In actual spectral measurement, it is usually need to know the bandwidth. In the case of a Czerny-Turner double monochromator, we measured its bandwidth in finite different wavelengths as well as slit widths. Bandwidth can be represented as a function of wavelength and slit width. After the experiment, we get bandwidth in some discrete wavelengths and slit widths, bandwidth in other wavelength and slit width can be computed through mathematical process of the data that already acquired.

The aim of this method is to determine the thickness of a transparent medium, close to the corneal thickness, using the angle at the first and second Purkinje images are aligned for a specific optical slit width. An optical slit is projected in an oblique angle relatively to the transparent medium, producing two different reflections in each medium surface (first and second Purkinje images). The slit is then moved until the first and second Purkinje images of the slit are aligned in such a way, that look as if they were a continuous slit. The slit width, the angle between the illumination and observation, and the medium index are used, then, to calculate the medium thickness. This method was implemented in a slit lamp and the central thicknesses (CT) of nine gas-permeable contact lenses (CL) were measured, with this method and a mechanical gauge and the results were compared. The mean CT difference ± standard deviation, between the two methods was 0.004 ± 0.008 mm with minimum and maximum absolute values of 0.002 and 0.019 mm. This technique showed good precision to measure the CT of CL and should be tried in human corneas.

The UIST instrument is a 1-5μm Imager Spectrometer for the UKIRT telescope. The instrument has a high spatial resolution, and is designed to critically sample image sizes of 0.24arcsec. The instrument weighs 750kg and measures approximately 1100x1000x700mm. The flexure specification for the instrument is to maintain the image at the slit within 10% of the narrowest slit width, which is 44μm wide. However combined flexure of the instrument and its supporting structure is expected to be many times more than this. To meet the UIST flexure requirements we propose use of an instrument specific component in the telescope pointing model, to correct for repeatable flexure. Two designs for mounting regimes are presented, together with flexure test results and a discussion of the use of a simple pointing correction. The first, flexible, truss design did not meet requirements and was replaced with a rigid truss system. The paper describes some lessons learned during the development of the UIST mounting scheme, which can be applied in other instrument designs.

A software package for analysis of small-angle scattering data are presented. The program DPSAS-PR enables a preliminary treatment of data obtained from different small angle cameras and the DPSAS-CR program corrects for a finite slit length and possibly for slit width distortions using the Lake, Schmidt and Vonk methods.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We present an astronomical cooled grating spectrometer (LonGSp--Longslit Gornergrat Spectrometer) designed to work at Telescopio Infrarosso del Gornergrat. The covered spectral range is 0.9 divided by 2.5 micrometers and the resolving power is between 300 and 4000 depending on the order and slit width. The spectrometer employs a NICMOS 3 (256 X 256) engineering array of which a subsection of 70 X 40 is used.

This paper describes some of optimizitions in high speed photography, such as optimizing the aperture width for each image speed of a studed object in a rotating mirror framing camera, optimizing the rotating mirror speed for each slit width in a smear camera, optimizing designs of a rotating mirror camera and intermittentmechanism in a intermittent camera through the differentiation and calculation by means of computer, and selecting the optimiz-ed photographic frequence in the application of high speed camera. Finally, we deduce it is possible that smear cameras can be partially replaced with the framing camera through the data processing in some cases.

A retrofit illuminator for the High Performance Condenser for the 100, 200, and 300 series Perkin-Eimer Micralign projection aligners is discussed. Comparisons of the major performance features between the two systems is made shoeing dramatic improvements in wafer through-put, a reduction of nearly 2,000 watts of electrical power consumption, reduction of the arc slit width, and significantly reduced maintenance time. Some SEM's of typical lithography are also presented.