AOS News - The Australian Optical Society - Macquarie University

AOS News Volume 25 Number 1 2011Horiba Scientific: HYPERSPECTRAL IMAGING: One-shot camera obtains simultaneous hyperspectral dataRecognizing the need for lower-cost,high-performance simultaneous imagecapture for fast-moving events such asexplosions (or even for some biologicalevents monitored through fluorophoreexcitation), scientists at HoribaScientific (Edison, NJ) in partnershipwith Snapshot Spectra (Pasadena, CA)have developed a patented, one-shotsimultaneous hyperspectral imaging(SHI) camera that simultaneouslycaptures spatial information and itscorresponding spectral information overthe wavelength range from 400 to 850 nm.In the SHI camera, a raw image (a)consists of a zero-order image thatreplicates the original scene surroundedby several higher diffraction ordersin both directions that contain allthe spatial and spectral informationin the scene. The “data cube” orhypercube (b) is generated by softwarereconstruction using the image in (a) asthe input. (Courtesy of Horiba Scientific)One-shot, simultaneous image captureTo obtain simultaneous hyperspectralinformation in a one-shot singlemeasurement step, the SHI camerarelies on a two-dimensional transmissiondispersive element sandwiched betweena pair of imaging lenses. The first orinput lens collimates the light comingfrom the scene of interest and thesecond lens re-images the diffracted lightfrom the dispersive element (betweenthe two lenses) onto the sensor. Theuniqueness of the system is based on thedispersive element design that createsa 2D diffraction pattern at the sensor(see figure). The image projected onthe sensor is an accurate representationof the field of view in the center of theimage (undiffracted zero order) andhigher diffracted orders around thecenter. Since the angle of diffractionis a function of the wavelength, withthe angle increasing from short (blue)to long (red) wavelengths, the higherorderdiffracted images are essentially“smeared” wavelengths across the sensorcontaining all the spectral informationin the scene. The hypercube is thengenerated from a software reconstructionalgorithm using the raw image data asinput.The robust design has no movingparts and can be applied to hazardousenvironments. Furthermore, thetechnique can use different dispersiveelements and sensors to optimizeresolution, sensitivity, and detectionspeed to suit the application of interest.“This technology enables spectral imagingapplications that were not possiblewith currently available technologies,especially ones with transient or dynamicscences,” says Francis Ndi, applicationsscientist at Horiba Scientific. “Its ruggedand portable design also makes it possibleto do such measurements in varied andharsh environments such as industrialas well as field work—given that it doesnot need a computer for acquisition.”—Gail Overton.New Gentec Maestro Touch Screen Single Channel, Power & Energy MonitorGentec Electro-Optics is proudto announce the new MAESTROLaser Power & Energy Monitor,their first device with fully TouchScreen controls based on a 5.6 inchcolor LCD screen.The main innovation of this devicecomes from its ease of use, thanksto an excellent accessibility to all themain functionalities, allowing youto improve your productivity in thelab. Another improvement on theMAESTRO is the data transfer andstorage that is now done directlyon a USB key. Furthermore, theMAESTRO is also equipped withall the interfaces necessary for aneasy and thorough utilization:Ethernet, RS-232, Analog Output,External Trigger and a USB comport for sending serial commandsvia a PC.For more information please contact Lastek at sales@lastek.com.au39