Transverse dynamics of speckles in output radiation of optical fiber and determination of intermode dispersion generated under probing of laser diode with GHz frequency deviation

2005 ◽  
Author(s):  
Garif G. Akchurin ◽  
Alexander G. Akchurin
Keyword(s):  
Optical Fiber ◽  
Laser Diode ◽  
Frequency Deviation ◽  
Output Radiation

Determination of the profile of the temperature field of material heated by continuous laser radiation

2020 ◽  
pp. 51-10
Author(s):  
B.A. Lapshinov ◽  
◽  
N.I. Timchenko ◽  
Keyword(s):  
Temperature Field ◽  
Optical Fiber ◽  
Prolonged Exposure ◽  
Radiation Spectrum ◽  
Visible Range ◽  
Continuous Laser ◽  
Surface Temperature Distribution ◽  
Continuous Radiation ◽  
Spectral Pyrometry

Spectral pyrometry was used to determine the surface temperature distribution of Si, Nb, Cu, and graphite samples when they were locally heated by continuous radiation of an Nd:YAG laser (λ = 1.064 μm). With prolonged exposure to radiation, a stationary temperature field was established in the samples. The thermal spectra were recorded with a small spectrometer in the visible range in the temperature range above 850 K. The optical fiber used to transmit the radiation spectrum to the spectrometer had an additional diaphragm with a diameter of 1 mm located at a certain distance from the fiber end, which ensured the locality of the recorded spectra. The optical fiber moved continuously along the sample, and the spectrometer recorded up to 100 spectra with a frequency of 5-10 Hz. The temperature profile of the samples was calculated based on the results of processing the spectra using the Spectral Pyrometry program.

Enhancement of Coupling Efficiency of Butterfly Package Laser Modules Based on Post-Weld-Shift Compensation

2011 ◽  
Vol 145 ◽  
pp. 109-113
Author(s):  
Jao Hwa Kuang ◽  
Tsung Pin Hung ◽  
Shian Huan Chiou ◽  
Chao Ming Hsu
Keyword(s):  
Optical Fiber ◽  
Laser Diode ◽  
Optical Design ◽  
Coupling Efficiency ◽  
Welding Process ◽  
Central Wavelength ◽  
Power Coupling ◽  
Finite Element Software ◽  
Numerical Predictions ◽  
Welding Sequence

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%.

scholarly journals The new device for determination of fiber content in individual plants of fiber flax

2019 ◽  
pp. 75-79
Author(s):  
Oleksandr Holoviy
Keyword(s):  
Laser Diode ◽  
Fiber Content ◽  
Fiber Flax ◽  
New Device

The article describes the design of the device for determining the fiber content in individual plants of flax, which is a special torsion scales of the new design. The principle of operation of the device is based on the transformation of the free end of the cantilever-mounted flat spring, to which the object of suspension is suspended, in the rotation of a mirror that reflects the laser diode beam on the scale. The device can be used in fibe flax breeding.

scholarly journals THz Signal Generator Using a Single DFB Laser Diode and the Unbalanced Optical Fiber Interferometer

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4862
Author(s):  
Blaž Pongrac ◽  
Denis Đonlagic ◽  
Matej Njegovec ◽  
Dušan Gleich
Keyword(s):  
Optical Fiber ◽  
Laser Diode ◽  
Optical Signal ◽  
Optical Path Difference ◽  
Sweep Rate ◽  
Path Difference ◽  
Optical Path ◽  
Signal Generator ◽  
Optical Frequency ◽  
Frequency Sweep

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).

Determination of the spatial extent of the focal point of a parabolic dish reflector using a red laser diode

2010 ◽  
Vol 35 (9) ◽  
pp. 1982-1990 ◽  
Author(s):  
J.S.P. Mlatho ◽  
M. McPherson ◽  
A. Mawire ◽  
R.J.J. Van den Heetkamp
Keyword(s):  
Laser Diode ◽  
Focal Point ◽  
Spatial Extent ◽  
Parabolic Dish
Sign in / Sign up

Export Citation Format

Share Document