A simple and novel method for measuring the chirp parameter of an intensity modulated light source

1999 ◽  
Vol 11 (6) ◽  
pp. 700-702 ◽  
Author(s):  
B. Kowalski ◽  
J. Debeau ◽  
R. Boittin
Keyword(s):  
Light Source ◽  
Intensity Modulated ◽  
Novel Method ◽  
Modulated Light

scholarly journals High-Power Broadband Frequency Chirped Intensity-Modulated Single-Frequency 1064-nm Laser

2020 ◽  
Vol 10 (13) ◽  
pp. 4450
Author(s):  
Kun Li ◽  
Suhui Yang ◽  
Xin Wang ◽  
Zhuo Li
Keyword(s):  
Laser Beam ◽  
Light Source ◽  
High Power ◽  
Maximum Output Power ◽  
Single Frequency ◽  
Maximum Output ◽  
Long Distance ◽  
Intensity Modulated ◽  
Microwave Radar ◽  
Modulated Light

Optical carried microwave radar (OCMR), combining the advantages of lidar and microwave radar, uses an intensity-modulated laser beam as the medium to detect the distance and velocity of objects. In order to achieve a high ranging resolution at long distance, a high-power frequency chirped intensity-modulated light source at a 1064-nm wavelength was developed. A low-power narrow-linewidth 1064-nm laser beam was input to a Mach-Zehnder electro-optic modulator (EOM), and the frequency of the EOM was tuned from 10 MHz to 2.1 GHz. The output from the EOM was coupled to a laser-diode-pumped ytterbium-doped fiber amplifier (YDFA). A maximum output power of 29.5 W was achieved from the YDFA. We measured the frequency characteristics of the modulated laser beams before and after amplification, respectively. The amplification process did not bring any obvious degeneration of the modulation in terms of the bandwidth, frequency stability, chirping linearity, and modulation depth. Our research presents a new approach of obtaining a high-power broad-band intensity-modulated light source for OCMR.

Widely wavelength tunable fast intensity-modulated light source for biophotonic applications

2017 ◽  
Vol 42 (14) ◽  
pp. 2790 ◽  
Author(s):  
Tzu-Feng Huang ◽  
Sheng-Hao Tseng ◽  
Hsien-Yi Wang ◽  
Ming-Che Chan
Keyword(s):  
Light Source ◽  
Intensity Modulated ◽  
Wavelength Tunable ◽  
Modulated Light

Phantom array and stroboscopic effects of a time-modulated moving light source during saccadic eye movement

2017 ◽  
Vol 50 (5) ◽  
pp. 772-786 ◽  
Author(s):  
C-S Lee ◽  
J-H Lee ◽  
H Pak ◽  
SW Park ◽  
D-W Song
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Light Source ◽  
Light Emitting Diode ◽  
Saccadic Eye Movements ◽  
Movement Speed ◽  
Light Sources ◽  
Saccadic Eye Movement ◽  
Modulated Light ◽  
Source Motion

This paper evaluates the detectability of the phantom array and stroboscopic effects during light source motion, eye movement and their combination, using time modulated light-emitting diode light sources. It is well known that the phantom array can be observed when time-modulated light sources are observed during saccadic eye movements. We investigated whether light source motion can cause similar effects when the subject has fixed eyes. In addition, we estimated the detectability threshold frequency for the combination of stroboscopic effect and the phantom array, which is named the stroboscopic-phantom array effect, during two eye movements in opposite directions under one directional rotating light source with variable speed. Our results indicate that one of the most important factors for the stroboscopic-phantom array effect is eye movement speed relative to the speed of the light source. Therefore, time-modulated moving light sources induce a stroboscopic effect in subjects with fixed eyes that is similar to the stroboscopic-phantom array effect observed during saccadic eye movement. Our findings are likely to be useful for predicting the stroboscopic effect and the stroboscopic-phantom array effect during the fast motion of time-modulated LED light sources, like multi-functional rear lamps, in automotive lighting applications.

A novel method for detecting light source for digital images forensic

2011 ◽  
Vol 19 (2) ◽  
Author(s):  
A. Roy ◽  
S. Mitra ◽  
R. Agrawal
Keyword(s):  
Forensic Science ◽  
Light Source ◽  
Digital Image ◽  
Digital Images ◽  
Experimental Results ◽  
New Method ◽  
Light Sources ◽  
Image Forensic ◽  
Morality Politics ◽  
Novel Method

AbstractManipulation in image has been in practice since centuries. These manipulated images are intended to alter facts — facts of ethics, morality, politics, sex, celebrity or chaos. Image forensic science is used to detect these manipulations in a digital image. There are several standard ways to analyze an image for manipulation. Each one has some limitation. Also very rarely any method tried to capitalize on the way image was taken by the camera. We propose a new method that is based on light and its shade as light and shade are the fundamental input resources that may carry all the information of the image. The proposed method measures the direction of light source and uses the light based technique for identification of any intentional partial manipulation in the said digital image. The method is tested for known manipulated images to correctly identify the light sources. The light source of an image is measured in terms of angle. The experimental results show the robustness of the methodology.

Effects of the photogenerated excess carriers on the thermal and elastic properties of n-type silicon excited with a modulated light source: Theoretical analysis

2019 ◽  
Vol 126 (18) ◽  
pp. 185102 ◽  
Author(s):  
D. K. Markushev ◽  
D. D. Markushev ◽  
S. Aleksić ◽  
D. S. Pantić ◽  
S. Galović ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Light Source ◽  
Elastic Properties ◽  
Type Silicon ◽  
Modulated Light

Magneto-optical spectroscopy with arbitrarily polarized intensity-modulated light in He4 atoms

2020 ◽  
Vol 101 (6) ◽  
Author(s):  
He Wang ◽  
Teng Wu ◽  
Haidong Wang ◽  
Xiang Peng ◽  
Hong Guo
Keyword(s):  
Optical Spectroscopy ◽  
Intensity Modulated ◽  
Modulated Light
Sign in / Sign up

Export Citation Format

Share Document