Authors:
Léa Chaccour
1
;
Guy Aubin
2
;
Kamel Merghem
2
;
Jean-Louis Oudar
2
;
Aghiad Khadour
3
;
Patrice Chatellier
3
and
Sophie Bouchoule
2
Affiliations:
1
IFSTTAR, Laboratoire LISIS, LPN-CNRS and UPR20, France
;
2
LPN-CNRS and UPR20, France
;
3
IFSTTAR and Laboratoire LISIS, France
Keyword(s):
Semiconductor Lasers, Vertical External Cavity Surface Emitting Lasers, Semiconductor Disk Lasers, Dual-Frequency Laser Emission, Laser Diodes for the Generation of Radio-Frequency Signals, Optical Sources for Optical Fiber Sensors.
Related
Ontology
Subjects/Areas/Topics:
Lasers and Photonic Components
;
Optical Communication Systems
;
Telecommunications
Abstract:
We aim at realizing an optically-pumped, dual-frequency VECSEL at telecom wavelength (1.5 µm) with a frequency difference in the radio-frequency (RF) range (around 11 GHz), to be used in a sensor unit based on Brillouin scattering in optical fibers. Laser emission of two orthogonally-polarized cavity modes with a controlled frequency difference is obtained by inserting a birefringent crystal in the VECSEL cavity. We have examined the influence of the different intra-cavity elements on the laser emission. It is shown that optimizing the free spectral range and the bandwidth of the intra-cavity Fabry-Perot etalon is of practical importance to achieve a stable single longitudinal laser emission for each of the two orthogonal polarizations. The optimization of the output power has also been investigated and it is concluded that up to 100 mW output power can be expected by adjusting the reflectivity of the output coupling mirror of the VECSEL cavity. The achievement of a highly-stable fre
quency difference is crucial for sensing applications. For this reason the influence of different parameters on the stability of the dual-frequency emission have been studied. It is concluded that mechanical vibrations are the main cause of the RF signal instability in our free-running VECSEL cavity. The design of a compact or mono-block cavity may allow to meet the stability requirements for our sensors.
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