43,881 research outputs found
Integrated filter and detector array for spectral imaging
A spectral imaging system having an integrated filter and photodetector array is disclosed. The filter has narrow transmission bands which vary in frequency along the photodetector array. The frequency variation of the transmission bands is matched to, and aligned with, the frequency variation of a received spectral image. The filter is deposited directly on the photodetector array by a low temperature deposition process. By depositing the filter directly on the photodetector array, permanent alignment is achieved for all temperatures, spectral crosstalk is substantially eliminated, and a high signal to noise ratio is achieved
Spectrometer integrated with a facsimile camera
This invention integrates a spectrometer capability with the basic imagery function of facsimile cameras without significantly increasing mechanical or optical complexity, or interfering with the imaging function. The invention consists of a group of photodetectors arranged in a linear array in the focal plane of the facsimile camera with a separate narrow band interference filter centered over each photodetector. The interference filter photodetector array is on a line in the focal plane of the facsimile camera along the direction of image motion due to the rotation of the facsimile camera's vertical mirror. As the image of the picture element of interest travels down the interference filter photodetector array, the photodetector outputs are synchronously selected and sampled to provide spectral information on the single picture element
The quest for the ideal photodetector for the next generation deep-underwater neutrino telescopes
We review photodetectors used in present running neutrino telescopes. After a
brief historical discourse, the photodetector requirements for the next
generation deep underwater neutrino telescopes are discussed. It is shown that
large area vacuum hybrid phototubes are the closest to the ideal photodetector
for such kind of applications when compared with other vacuum phototubes.Comment: 5 pages, 5 figure
All-optical pulse processing for advanced photonic communication system
This paper investigates the use of a two-photon absorption photodetector for high speed processing of ultrashort optical pulses in advanced photonic communication systems. Specifically the paper describes how the two-photon absorption photodetector maybe employed for chromatic dispersion monitoring in high-speed, wavelength division multiplexed networks, and also for reducing multiple access interference noise in an optical code division multiplexed system
Tailorable infrared sensing device with strain layer superlattice structure
An infrared photodetector is formed of a heavily doped p-type Ge sub x Si sub 1-x/Si superlattice in which x is pre-established during manufacture in the range 0 to 100 percent. A custom-tailored photodetector that can differentiate among close wavelengths in the range of 2.7 to 50 microns is fabricated by appropriate selection of the alloy constituency value, x, to establish a specific wavelength at which photodetection cutoff will occur
Interferometer direction sensor Patent
Michelson interferometer with photodetector for optical direction sensin
High Speed Mid-Wave Infrared Uni-traveling Carrier Photodetector
Mid-wave infrared (MWIR) frequency comb is expected to dramatically improve
the precision and sensitivity of molecular spectroscopy. For high resolution
application, high speed MWIR photodetector is one of the key components,
however, the commercially available high speed MWIR photodetector only has
sub-GHz bandwidth currently. In this paper, we demonstrate, for the first time
to our knowledge, a high speed mid-wave infrared (MWIR) uni-traveling carrier
photodetector based on InAs/GaSb type-II superlattice (T2SL) at room
temperature. The device exhibits a cutoff wavelength of 5.6{\mu}m, and 3dB
bandwidth of 6.58 GHz for a 20{\mu}m diameter device at 300K. These promising
results show the device has potential to be utilized in high speed applications
such as frequency comb spectroscopy, free space communication and others. The
limitations on the high frequency performance of the photodetectors are also
discussed
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