Focal Plane Array Camera Research Articles

Investigation of solid-phase peptide synthesis by the near-infrared multispectral imaging technique: a detection method for combinatorial chemistry.

A near-infrared (NIR) multispectral imaging spectrometer was used to monitor solid-phase peptide synthesis. This imaging spectrometer has fast scanning ability and high sensitivity because it is based on an acousto-optic tunable filter and a NIR InGaAs focal plane array camera. This NIR imaging instrument possesses all the advantages of conventional NIR spectrometers; namely, it can be used for noninvasive monitoring of the reactions and identification of the products during the solid-phase peptide synthesis of glycine, alanine, and valine mediated by aminomethylstyrene resin beads. The reaction was determined by monitoring either the decrease of the band at 1529 nm, which is due to the amine group on the beads, or the increase of the amide band generated at 1483 nm. The amine band at 1529 nm was also used to determine the presence of the Fmoc protecting groups and the efficiency of its removal. More importantly, this NIR imaging spectrometer has additional features that conventional NIR spectrometers cannot offer; namely, its ability to measure spectra at different positions within a sample. This feature was utilized for the first demonstration in which reactions of three different solid-phase peptide syntheses (in a three-compartment cell) were simultaneously monitored. As expected, the kinetics obtained for three reactions are similar to those obtained when the each of the reactions was individually determined. In this study, data recorded by 16 x 16 pixels were used to calculate a spectrum for each sample. However, a relatively good spectrum can be obtained by using data recorded by a single pixel. Since the NIR camera used in this camera is equipped with 240 x 320 pixels, this NIR mutispectral imaging technique is not limited to the three-compartment cell used in this study but rather can be used as the detection method for the solid-phase peptide synthesis in combinatorial chemistry.

In vivo infrared tomographic imaging of laser-heated blood vessels

We demonstrate a method for infrared tomographic imaging of the initial three-dimensional (3-D) temperature increase of in vivo blood vessels following pulsed laser exposure. Using a time-sequence of infrared images recorded by a fast focal plane array camera as input data, a reconstruction algorithm is used to compute the initial 3-D temperature increases in the chick chorioallantoic membrane and port wine stain in human skin. The noncontact tomographic imaging method is relevant to various laser therapies that rely on a photothermal mechanism for selective modification of tissue and may find diagnostic application to determine optimal laser dosimetry, position, and size of targeted subsurface chromophores.

Infrared Imaging of In Vivo Microvasculature Following Pulsed Laser Irradiation

Infrared emission images of the chick chorioallantoic membrane (CAM) microvasculature following pulsed laser irradiation were recorded using a high speed infrared focal plane array camera. A three-dimensional tomographic reconstruction algorithm was applied to compute the initial space-dependent temperature increase in discrete CAM blood vessels caused by light absorption. The proposed method may provide consistent estimates of the physical dimensions of subsurface blood vessels and may be useful in understanding a variety of biomedical engineering problems involving laser-tissue interaction. © 1998 Society of Photo-Optical Instrumentation Engineers.

Rapid, large area mapping of defect concentration in semiconductor wafers by infrared absorption

We report a fast, nondestructive method of mapping defect concentrations over large areas of semiconductor wafers. The method uses a platinum silicide staring focal plane array (FPA) camera to image wafers quickly and with high resolution in the near infrared band. The camera collects data simultaneously from 78,000 points on a 100 mm diameter wafer. For each point, the defect-related absorption coefficient was determined and converted to defect density. The entire process requires about 5 min. This method was demonstrated by measuring and mapping EL2 concentration in undoped semi-insulating liquid encapsulated Czochralski gallium arsenide wafers.

A passive millimeter wave camera for aircraft landing in low visibility conditions

Fog and low visibility conditions have hampered aviation since its inception. Fog-related accidents are numerous, and canceled take-offs and landings due to fog and low visibility conditions (Cat III) have significant economic impact on airlines, parcel carriers and general aviation. Millimeter waves have good propagation properties in weather and give adequate spatial resolution when used to image the forward scene. Passive millimeter wave focal plane array cameras are new sensors which, integrated into future guidance and landing systems, promise to be an effective aid, or alternative, to existing technology for aircraft landings and take-offs under Cat III conditions. They can produce visual-like radiometric images at real time frame rates (up to 30 Hz), and are directly amenable to image fusion with infrared and visible images. TRW has been actively involved in developing and productizing this technology both at the hardware and the system levels.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>