Broad Band Optical Power Limiting in Vanadium Doped Cd0.55Mn0 45Te Crystals

1997 ◽  
Vol 479 ◽  
Author(s):  
S. B. Trivedi ◽  
R. J. Chen ◽  
K. Grasza ◽  
S. W. Kutcher ◽  
G. V. J. Nathan ◽  
...  

AbstractA variety of approaches have been used for optical limiting in the past [1–6].A relatively new approach, an electro-optic power limiter (EOPL) has a simple and compact design, wavelength agile sensitivity, the ability to respond to coherent as well as incoherent radiation, low threshold and a large field of view (up to 15°). EOPL devices allow the transmission of low intensity background radiation while simultaneously blocking the damaging high intensity beam. We have demonstrated EOPL in the past using the II-VI semiconductors CdTe:In [7,8], CdTe:V [9] and ZnTe [10]. In this paper, we are reporting on EOPL using a new ternary II-VI semiconductor Cdl-xMnxTe:V. Cd0.55Mn0.45Te is capable of limiting optical radiation from visible (0.630.tm) to near infrared (1.5pm) wavelengths, which covers the wavelength ranges of both CdTe and ZnTe combined. Additionally, crystals of Cd0.55Mn0.45Te are relatively easier to grow than ZnTe. We report our preliminary results of optical limiting in Cd0.55Mn0.45Te:V at 0.780μm, 0.895μm, and 1.06μm, and we discuss the materials issues involved in improving and optimizing Cd1-xMnxTe for electro-optic power limiting.

1987 ◽  
Vol 115 ◽  
pp. 188-188
Author(s):  
M. Tapia ◽  
M. Roth ◽  
L.F. Rodríguez ◽  
J. Cantó ◽  
P. Persi ◽  
...  

GM24 is a small visible nebulosity in the vicinity of a molecular cloud. In this contribution we present the results of continuum (6-cm) and CO line (J = 1 → 0) radio observations, infrared maps, broad-band photometry and low-resolution spectroscopy as well as long-slit Echelle Ha spectroscopy. We found evidence that the GM24 = PP85 nebula is part of a larger region where star formation occurred in the past 104 years; the region is embedded in a typical molecular cloud with a dimension of ∼ 10 pc and mass of ∼104 M⊙. A compact radio H II region seems to be associated with GM24 and with one of the mid-infrared peaks detected. The nebula is most probably the visible part of an embedded H II region that is starting to emerge from the cloud. The other infrared peaks found in its vicinity (∼ 1 pc) are probably associated with less evolved stellar objects. The complex also shows an extended near-infrared flux which we believe to arise in a reflection nebula. From energy arguments, we found that the luminosity required to power the H II region and keep the cloud at the observed large temperature (TK ≅33 K), is ∼105 L⊙ which is consistent with the infrared total flux from the present measurements and those from IRAS of 4x104 L⊙; this corresponds to the flux of ∼3 BO ZAMS stars. The details of the present work have appeared in the Revista Mexicana de Astronomía y Astrofísica, Volume 11, 83, 1985.


1994 ◽  
Vol 374 ◽  
Author(s):  
Tallis Y. Chang ◽  
Ian McMichael ◽  
John H. Hong ◽  
Monte Khoshnevisan

AbstractWe present studies of an optical power limiter that uses a combination of the photoconductive and linear electro-optic effects. The electro-optic power limiter (EOPL), first demonstrated using CdTe in the near IR, possesses many desirable qualities including broadband wavelength responsivity, self-actuation, and low threshold power. One unique capability of EOPL, not found in any other nonlinear optical power limiter, is the fact that any light - coherent or incoherent - can be used. Our studies in CdTe, GaAs, and BSO crystals resulted in extending the wavelength range from the visible to MWIR wavelengths.


Nanoscale ◽  
2021 ◽  
Author(s):  
Jinsong Xiong ◽  
Qinghuan Bian ◽  
Shuijin Lei ◽  
Yatian Deng ◽  
Kehan Zhao ◽  
...  

Near-infrared (NIR) light induced photothermal cancer therapy using nanomaterials as photothermal agents has attracted considerable research interest over the past few years. As the key factor in the photothermal therapy...


Author(s):  
Xue Zhou ◽  
Jinmeng Xiang ◽  
Jiming Zheng ◽  
Xiaoqi Zhao ◽  
Hao Suo ◽  
...  

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) light source have great potential in non-destructive detection, promoting plant growth and night vision applications, while the discovery of a broad-band NIR phosphor still...


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud M. A. Eid ◽  
Ahmed Nabih Zaki Rashed ◽  
Iraj S. Amiri

AbstractThis work outlined the fast speed response and high modulation bandwidth through LiNbO3 electro-optic modulators. The refractive index is analyzed to estimate the switching voltage and modulation bandwidth for these modulators. The modulation voltage and data transmission data rates are analyzed and discussed clearly through LiNbO3 electro-optic modulators. The modulator’s performance efficiency is upgraded with the optimum modulator length of 10 mm and its thickness of 2 mm. The proposed modulators are compared with GaAs electrooptic modulators under various electro-optic modulators dimensions at 1300 nm near-infrared region and room temperature.


Author(s):  
Nidhi Rajesh Mavani ◽  
Jarinah Mohd Ali ◽  
Suhaili Othman ◽  
M. A. Hussain ◽  
Haslaniza Hashim ◽  
...  

AbstractArtificial intelligence (AI) has embodied the recent technology in the food industry over the past few decades due to the rising of food demands in line with the increasing of the world population. The capability of the said intelligent systems in various tasks such as food quality determination, control tools, classification of food, and prediction purposes has intensified their demand in the food industry. Therefore, this paper reviews those diverse applications in comparing their advantages, limitations, and formulations as a guideline for selecting the most appropriate methods in enhancing future AI- and food industry–related developments. Furthermore, the integration of this system with other devices such as electronic nose, electronic tongue, computer vision system, and near infrared spectroscopy (NIR) is also emphasized, all of which will benefit both the industry players and consumers.


2012 ◽  
Vol 185 ◽  
pp. 60-64
Author(s):  
Min Min Zhu ◽  
Ze Hui Du ◽  
Jan Ma

(100)-oriented PLZT ((Pb1-x, Lax) (Zry,Ti1-y)1-x/4O3, x/y=9/65) films of up to ~ 1.23 μm have been developed on LaAlO3single crystal substrate by magnetron sputtering. The as-grown PLZT thin films exhibit high optical transparency in visible and near-infrared light wavelength and high quadratic (Kerr) EO coefficients. Prism coupler measurements reveal that the PLZT thin films possess large refractive index, as high as 2.524 in TE model and 2.481 in TM model. The transparency of >70% in the range of λ= 500-1200 nm, the optic band gap of 3.42 eV and the quadratic electro-optic (EO) coefficient of 3.38 x 10-17(m/V)2have been measured in the films. Due to the large EO coefficient and the micrometric thickness, the as-developed PLZT films have great potential in developing longitudinal-or transverse-type EO devices in electric and optic field


2017 ◽  
Vol 121 (15) ◽  
pp. 153105 ◽  
Author(s):  
X. L. Hu ◽  
L. B. Sun ◽  
Q. J. Wu ◽  
L. S. Wang ◽  
S. A. Bai ◽  
...  
Keyword(s):  

2020 ◽  
Vol 501 (2) ◽  
pp. 2250-2267
Author(s):  
J Crass ◽  
A Bechter ◽  
B Sands ◽  
D King ◽  
R Ketterer ◽  
...  

ABSTRACT Enabling efficient injection of light into single-mode fibres (SMFs) is a key requirement in realizing diffraction-limited astronomical spectroscopy on ground-based telescopes. SMF-fed spectrographs, facilitated by the use of adaptive optics (AO), offer distinct advantages over comparable seeing-limited designs, including higher spectral resolution within a compact and stable instrument volume, and a telescope independent spectrograph design. iLocater is an extremely precise radial velocity (EPRV) spectrograph being built for the Large Binocular Telescope (LBT). We have designed and built the front-end fibre injection system, or acquisition camera, for the SX (left) primary mirror of the LBT. The instrument was installed in 2019 and underwent on-sky commissioning and performance assessment. In this paper, we present the instrument requirements, acquisition camera design, as well as results from first-light measurements. Broad-band SMF coupling in excess of 35 per cent (absolute) in the near-infrared (0.97–1.31 ${\mu {\rm m}}$) was achieved across a range of target magnitudes, spectral types, and observing conditions. Successful demonstration of on-sky performance represents both a major milestone in the development of iLocater and in making efficient ground-based SMF-fed astronomical instruments a reality.


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