Near Infrared High Angular Resolution Observations of Stars and Circumstellar Regions by the Technique of Lunar Occultations

1994 ◽  
Vol 158 ◽  
pp. 376-378
Author(s):  
T. Chandrasekhar ◽  
N. M. Ashok ◽  
Sam Ragland
Keyword(s):  
High Speed ◽  
Near Infrared ◽  
Angular Resolution ◽  
Infrared Region ◽  
High Angular Resolution ◽  
Filter Bandwidth ◽  
One Dimensional ◽  
Near Infrared Region ◽  
System Frequency ◽  
Source Structure

A program of High Angular Resolution observations of stars and their circumstellar regions using the technique of lunar occultations has been initiated at the 1.2 m telescope at Gurushikhar (24°39′ N, 72°47′ E), India. A liquid nitrogen cooled InSb detector based high speed Infrared photometer with millisecond data acquisition capabilities has been developed for the near Infrared region (1–5 μm) and eight occultations have been successfully observed in the K band (2.2 μm). The sources are (IRC No. -10578, +10013, +20034, +30094, +20190, +20200, +20073 and +00198. The diffraction pattern is clearly seen in all the observations. A convolution analysis involving the system frequency response, filter bandwidth and one dimensional source structure has been carried out to fit the data. System capability has been determined to be ~ 6 milliarcseconds.

scholarly journals Near Infrared High Angular Resolution Observations of Stars and Circumstellar Regions by Lunar Occultations

1995 ◽  
Vol 166 ◽  
pp. 399-399
Author(s):  
T. Chandrasekhar ◽  
N. M. Ashok ◽  
Sam Ragland
Keyword(s):  
High Speed ◽  
Near Infrared ◽  
Angular Resolution ◽  
Detection System ◽  
Optical Filter ◽  
High Angular Resolution ◽  
Filter Bandwidth ◽  
One Dimensional ◽  
Source Structure ◽  
Experimental Astronomy

The high angular resolution technique of lunar occultations enables one dimensional source structure in the direction of occultation to be extracted from the observed fringe pattern after detailed analysis taking into account the frequency response of the detection system, the optical filter bandwidth and the telescope size. A program of observing lunar occultations in the near infrared from 1.2m telescope at Gurushikhar, Mt Abu, India (72°47′E, 24°39′N, 1680m), is currently being pursued. Several occultations have been successfully observed in K band (2.2μm) including a day time event. The instrument used was a InSb based infrared high speed photometer, the details of which are given in a earlier paper (Ashok N.M., Chandrasekhar T. and Sam Ragland, 1994, Experimental Astronomy, 4, 177).

scholarly journals Large scale indium tin oxide (ITO) one dimensional gratings for ultrafast signal modulation in the visible spectral region

2020 ◽  
Vol 22 (13) ◽  
pp. 6881-6887 ◽  
Author(s):  
Michele Guizzardi ◽  
Silvio Bonfadini ◽  
Liliana Moscardi ◽  
Ilka Kriegel ◽  
Francesco Scotognella ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Large Scale ◽  
Near Infrared ◽  
Infrared Region ◽  
Visible Spectral Region ◽  
Signal Modulation ◽  
One Dimensional ◽  
Heavily Doped ◽  
Near Infrared Region

Indium tin oxide (ITO) is a heavily doped semiconductor with a plasmonic response in the near infrared region.

Saturable absorption in one-dimensional Sb_2Se_3 nanowires in the visible to near-infrared region

2016 ◽  
Vol 41 (9) ◽  
pp. 2049 ◽  
Author(s):  
Rajesh Kumar Yadav ◽  
Rituraj Sharma ◽  
J. Aneesh ◽  
P. Abhiramnath ◽  
K. V. Adarsh
Keyword(s):  
Near Infrared ◽  
Infrared Region ◽  
Saturable Absorption ◽  
One Dimensional ◽  
Near Infrared Region

Ligand Influence Versus Electronic Configuration of d-metal Ion in Determining the Fate of NIR Emission from LnIII Ions: A Case Study with CuII, NiII and ZnII Complexes.

2021 ◽  
Author(s):  
Abhineet Verma ◽  
Sk Saddam Hossain ◽  
Sailaja S Sunkari ◽  
Joseph Reibenspies ◽  
Satyen Saha
Keyword(s):  
Metal Ion ◽  
Selection Rule ◽  
Near Infrared ◽  
Electronic Configuration ◽  
Infrared Region ◽  
Direct Excitation ◽  
Characteristic Emission ◽  
Nir Emission ◽  
Near Infrared Region

Lanthanides (LnIII) are well known for their characteristic emission in the Near-Infrared Region (NIR). However, direct excitation of lanthanides is not feasible as described by Laporte’s parity selection rule. Here,...

Highly luminescent InP-In(Zn)P/ZnSe/ZnS core/shell/shell colloidal quantum dots with tunable emission synthesized based on growth-doping

2021 ◽  
Author(s):  
Cong Shen ◽  
Yan Qing Zhu ◽  
Zixiao Li ◽  
Jingling Li ◽  
Hong Tao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Near Infrared ◽  
Infrared Region ◽  
Colloidal Quantum Dots ◽  
High Quality ◽  
Promising Alternative ◽  
Lower Toxicity ◽  
Near Infrared Region ◽  
Inp Quantum Dots ◽  
Tunable Emission

InP quantum dots (QDs) are considered as the most promising alternative to Cd-based QDs with the lower toxicity and emission spectrum tunability ranging from visible to near-infrared region. Although high-quality...

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