scholarly journals NIMPOL: An Imaging Polarimeter for the Mid-infrared

1997 ◽  
Vol 14 (2) ◽  
pp. 179-188 ◽  
Author(s):  
Craig H. Smith ◽  
Toby J. T. Moore ◽  
David K. Aitken ◽  
Takuya Fujiyoshi
Keyword(s):  
Focal Plane ◽  
Optical Design ◽  
Focal Plane Array ◽  
Field Of View ◽  
Mid Infrared ◽  
Control Electronics ◽  
Infrared Wavelengths

AbstractWe have built an imaging polarimeter for use at mid-infrared wavelengths (i.e. N band or 8–13 μm). The detecting element is a 128 × 128 element Si:Ga Focal Plane Array, supplied by Amber Engineering, USA. The polarimeter itself provides diffraction limited images on a 4-m class telescope and has a field of view of about 32 arcsec of sky with 0·25 arcsec pixels. We describe the optical design, control electronics, observing modes and detector sensitivities. Also presented are some observational results to demonstrate the power of this new imaging polarimetric system.

Design of Compact Infrared Zoom Lens System

2012 ◽  
Vol 571 ◽  
pp. 324-327
Author(s):  
A Qi Yan ◽  
Deng Shan Wu ◽  
Hao Wang ◽  
Jian Zhong Cao ◽  
Jing Jin Ma ◽  
...  
Keyword(s):  
Focal Plane ◽  
Low Cost ◽  
Optical Design ◽  
Focal Plane Array ◽  
Relevant Information ◽  
Commercial Application ◽  
Zoom Lens ◽  
Lens System ◽  
Compact Design ◽  
Infrared Materials

Infrared zoom lens system with cooled focal plane array (FPA) detector is widely used in military application. Relevant information about optical design can be got easily, but research on infrared zoom lens system with low cost and high image quality for commercial application is less. This paper design a Compact infrared zoom lens system with only four lenses, using an uncooled focal plane array (FPA) with 384×288 pixels with zoom ratio 3:1. Because of large F number and less lenses, transmission of the whole zoom system is greatly improved. NETD and MRTD of infrared system will be satisfying by this compact design. There is no special surface such as diffractive surface, HOE in zoom lens system, and only Ge and Znse infrared materials are chosen which result in lower production cost of infrared zoom lens system for commercial applications.

scholarly journals SPHERICAL PRIMARY MIRROR IN TELESCOPES WITH COMPLEX (MULTI-ELEMENT) OPTICAL DESIGNS

2021 ◽  
Vol 34 ◽  
pp. 81-84
Author(s):  
S.V. Podlesnyak ◽  
N.N. Fashchevsky ◽  
Yu.N. Bondarenko ◽  
S.M. Andrievsky
Keyword(s):  
Wave Front ◽  
Focal Plane ◽  
Optical Design ◽  
Effective Field ◽  
Field Of View ◽  
Spherical Mirror ◽  
Primary Mirror ◽  
Reflected Wave ◽  
Aperture Ratio

An optical design for telescope with spherical primary mirror, planoidal surface and two-lens corrector is discussed. The spherical mirror hasn aperture ratio 1/2.69. After reflection from the spherical mirror, the wave front falls on a planoidal surface and “forms” the reflected wave front from a virtual mirror with e 2 = 1.576. After passing the two-lens corrector, the light is collected in the focal plane. A dot diagram in the focal plane shows that all three-order aberrations are successfully corrected. The effective field of view is 2 degrees. The aperture ratio is 1/2.28.

scholarly journals A SOLAR MID-INFRARED TELESCOPE

2019 ◽  
Vol 55 (1) ◽  
pp. 11-16
Author(s):  
J. E. Mendoza-Torres ◽  
J. S. Palacios-Fonseca ◽  
M. Velázquez-de-la-Rosa ◽  
P. Rodríguez-Montero ◽  
A. De-Roa-Campoy ◽  
...  
Keyword(s):  
Control Systems ◽  
Focal Plane ◽  
Angular Resolution ◽  
Signal To Noise Ratio ◽  
Black Body ◽  
Field Of View ◽  
Solar Telescope ◽  
Signal To Noise ◽  
Mid Infrared ◽  
Infrared Telescope

We developed a mid infrared (MIR) solar telescope, centered at 10 µm. Various optical layouts were analyzed based on computer simulations and a RitcheyChretien 6-inches telescope was selected with a plate scale of 2.5′′/mm using a pyroelectric 4 × 16 pixels detector. The angular resolution is 36′′/pixel with a field of view of 9.6′×2.4′. Two germanium filters are used, one at the aperture of thetelescope and another near its focal plane. The detector was characterized with alaboratory black-body. The count values follow a linear relation with the blackbody temperature. The control systems for both the telescope and the detectorwere developed. Proper mechanical supports were designed for the filters, detectorand electronics. The system has been integrated and a user interface was developed. Preliminary observations have been made giving a signal-to-noise ratio of ≈ 1000.

scholarly journals Okayama Astrophysical Observatory Wide-Field Camera

2019 ◽  
Vol 71 (6) ◽  
Author(s):  
Kenshi Yanagisawa ◽  
Yasuhiro Shimizu ◽  
Kiichi Okita ◽  
Daisuke Kuroda ◽  
Hironori Tsutsui ◽  
...  
Keyword(s):  
Focal Plane ◽  
Near Infrared ◽  
Galactic Plane ◽  
Focal Plane Array ◽  
Variable Stars ◽  
Field Of View ◽  
Wide Field

Abstract We report on the development of a wide-field near-infrared (0.9–2.5$\, \mu$m) camera built as a renewal of the existing classical Cassegrain 0.91 m telescope at Okayama Astrophysical Observatory. The optics system was replaced with fast hybrid optics (f/2.5) composed of forward Cassegrain optics and quasi-Schmidt optics, which results in an effective image circle of 52 mm diameter on the focal plane. The new camera, called the Okayama Astrophysical Observatory Wide-Field Camera (OAOWFC), has imaging capabilities in the $Y$, $J$, $H$, and $K_{\rm s}$ bands over a field of view of $0.^{\!\!\!\circ }47 \times 0.^{\!\!\!\circ }47$ with a HAWAII-1 HgCdTe PACE focal plane array. The primary purpose of OAOWFC is to search for variability in the Galactic plane in the $K_{\rm s}$ band and to promptly follow up transients. We have demonstrated a photometric repeatability of 2% in the densest field in the northern Galactic plane and successfully discovered previously unreported variable stars. The observations of OAOWFC are fully autonomous, and we started scientific operations in 2015 April.

Real-Time, Mid-Infrared Spectroscopic Imaging Microscopy Using Indium Antimonide Focal-Plane Array Detection

1995 ◽  
Vol 49 (5) ◽  
pp. 672-678 ◽  
Author(s):  
E. Neil Lewis ◽  
Ira W. Levin
Keyword(s):  
Real Time ◽  
Focal Plane ◽  
Tissue Sample ◽  
Spectroscopic Imaging ◽  
Focal Plane Array ◽  
Array Detector ◽  
Mid Infrared ◽  
Infrared Spectroscopic ◽  
Dielectric Filter ◽  
Infrared Spectroscopic Imaging

A different approach toward mid-infrared spectroscopic imaging microscopy is introduced in which instrumentation is designed about an InSb multichannel, focal-plane array detector and a variable-bandpass dielectric filter. The system may be configured for either macroscopic or microscopic applications, and high-fidelity, chemically specific images may be acquired in real time. With the dielectric filter used in this assembly, continuous tuning is provided for the infrared 4000–2320 cm−1 spectral region with spectral resolutions of approximately 35–18 cm−1 at the extremes of this wavelength interval. The functioning of the imaging microscope is demonstrated with samples including polystyrene microspheres, preparations of lipids and an amino acid embedded in KBr disks, and a tissue sample derived from a coronal slice of a monkey cerebellum.

Vibrational Spectroscopic Microscopy: Raman, Near-Infrared and Mid-Infrared Imaging Techniques

1995 ◽  
Vol 1 (1) ◽  
pp. 35-46
Author(s):  
E. Neil Lewis ◽  
Ira W. Levin
Keyword(s):  
Focal Plane ◽  
Near Infrared ◽  
Imaging Techniques ◽  
Spectroscopic Imaging ◽  
Focal Plane Array ◽  
Acid Mixture ◽  
Infrared Focal Plane Array ◽  
Mid Infrared ◽  
Array Detectors ◽  
Infrared Spectral

New instrumental approaches for performing vibrational Raman, near-infrared and mid-infrared spectroscopic imaging microscopy are described. The instruments integrate imaging quality filters such as acousto-optic tunable filters (AOTFs), with visible charge-coupled device (CCD) and infrared focal-plane array detectors. These systems are used in conjunction with infinity-corrected, refractive microscopes for operation in the visible and near-infrared spectral regions and with Cassegrainian reflective optics for operation in the mid-infrared spectral interval. Chemically specific images at moderate spectral resolution (2 nm) and high spatial resolution (1 μm) can be collected rapidly and noninvasively. Image data are presented containing 128 × 128 pixels, although significantly larger format images can be collected in approximately the same time. The instruments can be readily configured for both absorption and reflectance spectroscopies. We present Raman emission images of polystyrene microspheres and a lipid/amino acid mixture and near-infrared images of onion epidermis and a hydrated phospholipid dispersion. Images generated from mid-infrared spectral data are presented for a KBr disk containing nonhomogeneous domains of lipid and for 50-μm slices of monkey cerebellum. These are the first results illustrating the use of infrared focal-plane array detectors as chemically specific spectroscopic imaging devices and demonstrating their application in biomolecular areas. Extensions and future applications of the various vibrational spectroscopic imaging techniques are discussed.

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