Reproducing the units of radiation strength and energy intensity for continuous-wave continuous-spectrum optical radiation in the wavelength range 0.2?10.6 ?m

1983 ◽  
Vol 26 (12) ◽  
pp. 985-988 ◽  
Author(s):  
L. V. Vlasov ◽  
V. V. Bacherikov ◽  
N. A. Morozov ◽  
L. N. Samoilov ◽  
V. I. Sapritskii ◽  
...  
Keyword(s):  
Continuous Spectrum ◽  
Wavelength Range ◽  
Optical Radiation ◽  
Energy Intensity ◽  
Continuous Wave

Global registration by optical radiation of lightning discharges on aboard a low-orbit spacecraft

2021 ◽  
Author(s):  
V.S. Chudnovsky ◽  
L.S. Chudnovsky ◽  
Yu.P. Vagin ◽  
A.N. Pleshanov ◽  
K.E. Tyupikov
Keyword(s):  
Wavelength Range ◽  
Optical Radiation ◽  
False Alarms ◽  
Information Flows ◽  
Range Finding ◽  
Global Registration ◽  
Lightning Detection ◽  
Lightning Discharges ◽  
The Difference ◽  
Finding Method

Registration of the coordinates of lightning by their optical radiation has already been implemented on geostationary spacecraft in the wavelength range of 777.4 nm. However, the algorithms for processing the registered signals, as well as the volumes of information flows, have not yet been sufficiently studied. The choice of the sensor for the global registration of optical radiation of lightning on board a low-orbit spacecraft is substantiated. The prospects of using photodiodes in the difference-ranging method for determining coordinates are shown.The characteristics of lightning detection using matrices and LEDs have been studied. The prospects of using photodiodes in the differential-range-finding method for determining coordinates are shown. It is shown that the registration of optical lightning radiation on board the spacecraft by photodiodes provides the characteristics of detection and false alarms of a higher quality compared with the use of CCD matrices.

scholarly journals Room-temperature continuous-wave operation in the telecom wavelength range of GaSb-based lasers monolithically grown on Si

APL Photonics ◽  
2017 ◽  
Vol 2 (6) ◽  
pp. 061301 ◽  
Author(s):  
A. Castellano ◽  
L. Cerutti ◽  
J. B. Rodriguez ◽  
G. Narcy ◽  
A. Garreau ◽  
...  
Keyword(s):  
Wavelength Range ◽  
Room Temperature ◽  
Continuous Wave ◽  
Continuous Wave Operation ◽  
Telecom Wavelength

scholarly journals Synchronization of pulsed and continuous-wave IMPATT oscillators in the millimeter wavelength range. Part 2. Stabilizing microwave parameters of synchronized generators

2021 ◽  
pp. 17-29
Author(s):  
M. F. Karushkin
Keyword(s):  
Output Power ◽  
Wavelength Range ◽  
Continuous Wave ◽  
Power Level ◽  
Output Power Level ◽  
External Signal ◽  
Power Sources ◽  
Impatt Diode ◽  
Millimeter Wavelength ◽  
Impatt Diodes

This is the second part of the two-part article, which summarizes the state-of-the-art results in the development of synchronized oscillators based on IMPATT (IMPact ionization Avalanche Transit-Time) diodes. The first part of the paper presented the electrodynamic design of oscillators, which contain a resonant oscillatory system with silicon IMPATT diodes and are synchronized by an external source of microwave oscillations. The second part of the paper considers the methods for stabilizing the parameters of IMPATT oscillators, which make it possible to create coherent power sources in the millimeter wavelength range. The specifics of pulse generators lies in the change in frequency within the microwave pulse relative to the change in temperature, which leads to a change in the impedance of the diode and thus to a phase change with respect to the synchronizing signal. Phase modulation is reduced or completely eliminated (which is necessary to ensure the coherence of the microwave transmitter) by using current compensation, i.e., by using the control current pulse with a special shape. The study demonstrates the expediency of introducing additional heating of the semiconductor structure of the IMPATT diode, which allows the initial temperature of the IMPATT diode in the region of the leading edge of each pulse to remain virtually constant and independent of the ambient temperature. Using these methods on silicon double-drift IMPATT diodes allowed creating synchronized oscillators with high frequency stability and an output power level from 20 to 150 W, which have a high degree of coherence in the synchronization mode with an external signal. The paper also presents the designs and parameters of coherent microwave power sources in the short-wave part of the millimeter wavelength range using the nonlinear properties of the IMPATT diodes in the radio-pulse conversion mode. This mode makes it possible to provide the output power level of the signal at the n-th harmonic Pout ≈1/n, which significantly exceeds the achieved characteristics of the frequency multipliers with charge accumulation, where Pout ≈ 1/n2. The output power of such devices is achieved at the level of 50–20 mW in the 75–180 GHz frequency range with a frequency multiplication factor of 1–15.

200/spl deg/C, 96-nm wavelength range, continuous-wave lasing from unbonded GaAs MOVPE-grown vertical cavity surface-emitting lasers

1995 ◽  
Vol 7 (5) ◽  
pp. 441-443 ◽  
Author(s):  
R.A. Morgan ◽  
M.K. Hibbs-Brenner ◽  
T.M. Marta ◽  
R.A. Walterson ◽  
S. Bounnak ◽  
...  
Keyword(s):  
Wavelength Range ◽  
Continuous Wave ◽  
Cavity Surface ◽  
Surface Emitting Lasers ◽  
Vertical Cavity Surface ◽  
Emitting Lasers ◽  
Vertical Cavity

High power continuous-wave GaSb-based superluminescent diodes as gain chips for widely tunable laser spectroscopy in the 1.95–2.45 μm wavelength range

2015 ◽  
Vol 107 (1) ◽  
pp. 011103 ◽  
Author(s):  
K. Vizbaras ◽  
E. Dvinelis ◽  
I. Šimonytė ◽  
A. Trinkūnas ◽  
M. Greibus ◽  
...  
Keyword(s):  
Laser Spectroscopy ◽  
Wavelength Range ◽  
High Power ◽  
Continuous Wave ◽  
Tunable Laser ◽  
Superluminescent Diodes

scholarly journals Purity Analysis of Gases Used in the Preparation of Reference Gas Standards Using a Versatile OPO-Based CRDS Spectrometer

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Stefan Persijn
Keyword(s):  
Greenhouse Gases ◽  
Wavelength Range ◽  
High Power ◽  
Continuous Wave ◽  
Highly Sensitive ◽  
Purity Analysis ◽  
Wide Wavelength Range ◽  
Gas Standards

Preparation of accurate reference gas standards at low amount fractions such as for greenhouse gases requires highly sensitive instrumentation to determine the purity of the gases used in the preparation. For this purpose, a versatile CRDS spectrometer has been constructed at VSL based on high-power, continuous wave OPOs covering a very wide wavelength range of 2.3–5.1 µm. Due to the use of passivated materials, the spectrometer is also suitable for the measurement of reactive impurities. Details of the spectrometer are presented together with several examples of purity analysis.

Reproducing the units of energy-brightness spectral density, radiation strength spectral density, and energy intensity spectral density for continuous radiation in the wavelength range 0.22?10.6 ?m

1983 ◽  
Vol 26 (12) ◽  
pp. 982-985 ◽  
Author(s):  
N. A. Morozov ◽  
V. V. Bacherikov ◽  
L. V. Vlasov ◽  
L. N. Samoilov ◽  
V. I. Sapritskii ◽  
...  
Keyword(s):  
Spectral Density ◽  
Wavelength Range ◽  
Energy Intensity ◽  
Continuous Radiation ◽  
Energy Brightness

Photothermal Response of Tissue Phantoms Containing Multi-Walled Carbon Nanotubes

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Saugata Sarkar ◽  
Jessica Fisher ◽  
Christopher Rylander ◽  
Marissa Nichole Rylander
Keyword(s):  
Carbon Nanotubes ◽  
Wavelength Range ◽  
Optical Radiation ◽  
Thermal Response ◽  
Temperature Elevation ◽  
Incident Laser ◽  
Transmission Electron ◽  
Tissue Phantoms ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Inclusion of multi-walled carbon nanotubes (MWNTs) into tissue prior to laser therapy has the potential to enhance the selectivity and effectiveness of cancer therapy by providing greater and more controlled thermal deposition. The purpose of this study was to investigate the optical and thermal response of tissue representative phantoms containing MWNTs to optical radiation. Tissue representative phantoms 20 mm in diameter and 1 mm in thickness were created from sodium alginate. Following the inclusion of MWNTs (900 nm in length, 40–60 nm in diameter) in phantoms, the distribution of MWNTs was observed using transmission electron microscopy. A predominantly, evenly dispersed and randomly oriented distribution of MWNTs was observed with a rare presence of MWNT clustering or clumping. In order to characterize the response of MWNT inclusion on optical properties of phantoms, the transmittance and reflectance spectra of phantoms with and without MWNT inclusion were measured with a spectrophotometer over a wavelength range of 200–1400 nm. Inclusion of MWNTs in phantoms dramatically enhanced light absorption across the entire wavelength range as evidenced by a diminished transmittance and reflectance compared with phantoms without MWNTs. In order to evaluate the spatiotemporal temperature distribution associated with laser irradiation of phantoms with and without MWNTs, the temperature was measured at discrete radial distances from the center of the incident laser beam using thermocouples. The rate of temperature increase and peak temperature for phantoms containing MWNTs was much greater compared with phantoms without MWNTs at all measurement locations. In conclusion, MWNT inclusion in tissue phantoms increases the optical absorption and temperature elevation, which may enable more effective photothermal therapies of human disease utilizing lasers.

Continuous-wave operation of type-I quantum well DFB laser diodes emitting in 3.4 [micro sign]m wavelength range around room temperature

2011 ◽  
Vol 47 (1) ◽  
pp. 46 ◽  
Author(s):  
L. Naehle ◽  
S. Belahsene ◽  
M.von. Edlinger ◽  
M. Fischer ◽  
G. Boissier ◽  
...  
Keyword(s):  
Quantum Well ◽  
Wavelength Range ◽  
Room Temperature ◽  
Continuous Wave ◽  
Laser Diodes ◽  
Type I ◽  
Continuous Wave Operation ◽  
Dfb Laser
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