12,338 research outputs found
Generation of pulsed dual wavelength erbium doped fiber laser
Single and dual wavelength fiber lasers and pulsed fiber lasers are well-known to be used for various applications. In the generation of dual wavelength fiber lasers and pulsed fiber lasers, the researchers found the mode competition among the dual wavelength is caused by the cross-gain saturation and strong homogeneous line broadening faced by erbium doped fiber (EDF). Therefore, the aim of this thesis is to generate a single and dual wavelength fiber laser and pulsed fiber laser by using fiber Bragg grating (FBG) in single ring and Figure-8 configurations at 1550 nm and 1560 nm. Analysis and optimization on single wavelength fiber laser and single wavelength pulsed fiber laser give a peak power of -10.70 dBm (8.51x10-2 mW) and -54.01 dBm (3.97x10-6 mW) with signal to noise ratio (SNR) of 59.70 dB and 10.29 dB, respectively, at 1550 nm. Similarly, at 1560 nm, this gives a peak power of -13.60 dBm (4.37x10-2 mW) and -60.00 dBm (1.00x10-6 mW) with SNR of 57.60 dB and 8.78 dB, respectively. For dual wavelength fiber laser and dual wavelength pulsed fiber laser, this gives a peak power of -12.90 dBm (5.13x10-2 mW) and -54.03 dBm (3.95x10-6 mW) at 1550 nm and a peak power of -14.80 dBm (3.24x10-2 mW) and -57.99 dBm (1.59x10-6 mW) at 1560 nm, respectively. The SNR obtained for 1550 nm and 1560 nm for dual wavelength fiber laser and dual wavelength pulsed fiber laser are 55.38 dB and 11.16 dB and 53.58 dB and 11.27 dB, respectively. The repetition rate of single and dual wavelength pulsed fiber laser is 2.878 MHz. It can be concluded that single and dual wavelength fiber lasers are successfully generated using single ring and figure-8 configurations whereas single and dual wavelength pulsed fiber laser are generated using only Figure-8 configuration due to mode locking occurrence. The polarization inside the cavity is controlled to solve mode competition and homogeneous in EDF, in order to obtain a stable dual wavelength
The generation of dual wavelength pulse fiber laser using fiber bragg grating
A stable simple generation of dual wavelength pulse fiber laser on experimental method is proposed and demonstrated by using Figure eight circuit diagram. The generation of dual wavelength pulse fiber laser was proposed using fiber Bragg gratings (FBGs) with two different central wavelengths which are 1550 nm and 1560 nm. At 600 mA (27.78 dBm) of laser diode, the stability of dual wavelength pulse fiber laser appears on 1550 nm and 1560 nm with the respective peak powers of -54.03 dBm and -58.00 dBm. The wavelength spacing of the spectrum is about 10 nm while the signal noise to ratio (SNR) for both peaks are about 8.23 dBm and 9.67 dBm. In addition, the repetition rate is 2.878 MHz with corresponding pulse spacing of about 0.5 μs, is recorded
Dual-wavelength thulium fluoride fiber laser based on SMF-TMSIF-SMF interferometer as potential source for microwave generationin 100-GHz region
A dual-wavelength thulium-doped fluoride
fiber (TDFF) laser is presented. The generation of the TDFF
laser is achieved with the incorporation of a single modemultimode-
single mode (SMS) interferometer in the laser
cavity. The simple SMS interferometer is fabricated using the
combination of two-mode step index fiber and single-mode fiber.
With this proposed design, as many as eight stable laser lines
are experimentally demonstrated. Moreover, when a tunable
bandpass filter is inserted in the laser cavity, a dual-wavelength
TDFF laser can be achieved in a 1.5-μm region. By heterodyning
the dual-wavelength laser, simulation results suggest that the
generated microwave signals can be tuned from 105.678 to
106.524 GHz with a constant step of �0.14 GHz. The presented
photonics-based microwave generation method could provide
alternative solution for 5G signal sources in 100-GHz region
Non-equilibrium dynamics in the dual-wavelength operation of Vertical external-cavity surface-emitting lasers
Microscopic many-body theory coupled to Maxwell's equation is used to
investigate dual-wavelength operation in vertical external-cavity
surface-emitting lasers. The intrinsically dynamic nature of coexisting
emission wavelengths in semiconductor lasers is associated with characteristic
non-equilibrium carrier dynamics which causes significant deformations of the
quasi-equilibrium gain and carrier inversion. Extended numerical simulations
are employed to efficiently investigate the parameter space to identify the
regime for two-wavelength operation. Using a frequency selective intracavity
etalon, two families of modes are stabilized with dynamical interchange of the
strongest emission peaks. For this operation mode, anti-correlated intensity
noise is observed in agreement with the experiment. A method using effective
frequency selective filtering is suggested for stabilization genuine
dual-wavelength output.Comment: 15 pages, 7 figure
Dual-wavelength system monitors deposition of films - A concept
System monitors fabrication of high-quality optical filters and other precise film deposition operations. System generates output signal of an element that changes rapidly when deposition process changes or stops, and eliminates defects of single-wavelength systems. Five additional advantages of dual-wavelength system are listed
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