Feedback type of laser diode interferometer with an optical fiber

1996 ◽  
Author(s):  
Takamasa Suzuki ◽  
Takao Okada ◽  
Osami Sasaki ◽  
Takeo Maruyama
2011 ◽  
Vol 109 ◽  
pp. 237-243
Author(s):  
Hong Xiu Zhu ◽  
Hao Zheng ◽  
Hong Bo Zhang ◽  
Xin Wang ◽  
Bo Xi Yang ◽  
...  

According to the absorption spectrum, combined with CO distribution feedback type laser diode (DFB-LD) light source, we selected R a center for 1567.3 nm as the wavelength of the absorption spectrum line. Comprehensively using of prism of gas chamber and harmonic detection technology, we constructed the optical fiber CO concentration measurement system. Through the stepping motor regulation height, it changes indoor prism gas effective absorption process, adjusts the light sensitivity system.


2011 ◽  
Vol 145 ◽  
pp. 109-113
Author(s):  
Jao Hwa Kuang ◽  
Tsung Pin Hung ◽  
Shian Huan Chiou ◽  
Chao Ming Hsu

When fabricating laser diode transceiver modules, the coupling efficiency can be improved via a laser hammering process, in which additional, calculated spot welds are performed at key locations within the package in order to compensate for post-weld shift. The present study performs a numerical investigation into the post-weld-shift compensation of a butterfly laser module package incorporating a lensed optical fiber and a laser diode with a central wavelength of 980 nm. In performing the simulations, the deformation of the package components during the welding process is modeled using Marc finite element software. Furthermore, the laser power coupling efficiency is estimated using the commercial Zemax optical design program. It is shown that the numerical predictions for the coupling power in the laser diode transceiver module are in good agreement with the experimental results. The optimal welding sequence which minimizes the post-weld shift of the optical fiber relative to the laser diode is determined. It is shown that the corresponding coupling efficiency is equal to 69%. Finally, it is shown that by performing an optimized laser hammering process, the coupling efficiency can be improved to around 99%.


Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4862
Author(s):  
Blaž Pongrac ◽  
Denis Đonlagic ◽  
Matej Njegovec ◽  
Dušan Gleich

This paper presents a frequency-modulated optical signal generator in the THz band. The proposed method is based on a fast optical frequency sweep of a single narrowband laser diode used together with an optical fiber interferometer. The optical frequency sweep using a single laser diode is achieved by generating short current pulses with a high amplitude, which are driving the laser diode. Theoretical analysis showed that the modulation frequency could be changed by the optical path difference of the interferometer or optical frequency sweep rate of a laser diode. The efficiency of the optical signal generator with Michelson and Fabry–Perot interferometers is theoretically analyzed and experimentally evaluated for three different scenarios. Interferometers with different optical path differences and a fixed optical frequency sweep rate were used in the first scenario. Different optical frequency sweep rates and fixed optical path differences of the interferometers were used in the second scenario. This paper presents a method for optical chirp generation using a programmable current pulse waveform, which drives a laser diode to achieve nonlinear optical sweep with a fixed optical path difference of the interferometer. The experimental results showed that the proposed signals could be generated within a microwave (1–30 GHz) and THz band (0.1–0.3 THz).


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