Open AccessCoherence function control of Quantum Dot Superluminescent Light Emitting Diodes by frequency selective optical feedback
Author(s) -
M. Błażek,
Wolfgang Elsäßer,
M. Hopkinson,
P. Resneau,
M. Krakowski,
M. Rossetti,
Paolo Bardella,
Mariangela Gioannini,
Ivo Montrosset
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.013365
Subject(s) - superluminescent diode , optics , coherence (philosophical gambling strategy) , optical coherence tomography , optoelectronics , bandwidth (computing) , interferometry , wavelength , physics , coherence length , diode , amplified spontaneous emission , optical power , materials science , laser , computer science , telecommunications , superconductivity , quantum mechanics
Low coherent light interferometry requires broad bandwidth light sources to achieve high axial resolution. Here, Superluminescent Light Emitting Diodes (SLDs) utilizing Quantum Dot (QD) gain materials are promising devices as they unify large spectral bandwidths with sufficient power at desired emission wavelengths. However, frequently a dip occurs in the optical spectrum that translates into high side lobes in the coherence function thereby reducing axial resolution and image quality. We apply the experimental technique of frequency selective feedback to shape the optical spectrum of the QD-SLD, hence optimizing the coherence properties. For well-selected feedback parameters, a strong reduction of the parasitic side lobes by a factor of 3.5 was achieved accompanied by a power increase of 40% and an improvement of 10% in the coherence length. The experimental results are in excellent agreement with simulations that even indicate potential for further optimizations.