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
2020 ◽  
Vol 10 (13) ◽  
pp. 4450
Author(s):  
Kun Li ◽  
Suhui Yang ◽  
Xin Wang ◽  
Zhuo Li

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.


2021 ◽  
Author(s):  
Thomas Würthwein ◽  
Kristin Wallmeier ◽  
Maximilian Brinkmann ◽  
Tim Hellwig ◽  
Niklas Lüpken ◽  
...  

2017 ◽  
Vol 50 (5) ◽  
pp. 772-786 ◽  
Author(s):  
C-S Lee ◽  
J-H Lee ◽  
H Pak ◽  
SW Park ◽  
D-W Song

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.


2019 ◽  
Vol 126 (18) ◽  
pp. 185102 ◽  
Author(s):  
D. K. Markushev ◽  
D. D. Markushev ◽  
S. Aleksić ◽  
D. S. Pantić ◽  
S. Galović ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document