Coherence function control of Quantum Dot Superluminescent Light Emitting Diodes by frequency selective optical...

Area of Science:

• Optoelectronics
• Quantum Dot Superluminescent Light Emitting Diodes (QD-SLDs)
• Low Coherent Light Interferometry

Background:

• High axial resolution in low coherent light interferometry necessitates broad bandwidth light sources.
• Quantum Dot Superluminescent Light Emitting Diodes (QD-SLDs) offer broad spectral bandwidths and sufficient power, making them promising for this application.
• A common issue with QD-SLDs is spectral dips, leading to high side lobes in the coherence function, which degrade axial resolution and image quality.

Purpose of the Study:

• To experimentally optimize the spectral properties of Quantum Dot Superluminescent Light Emitting Diodes (QD-SLDs).
• To mitigate spectral dips and reduce side lobes in the coherence function.
• To enhance axial resolution and image quality in low coherent light interferometry applications.

Main Methods:

• Implementation of an experimental frequency selective feedback technique.
• Shaping the optical spectrum of the QD-SLD to improve coherence properties.
• Comparison of experimental results with simulations for validation and further optimization.

Main Results:

• Achieved a significant reduction in parasitic side lobes by a factor of 3.5.
• Observed a 40% increase in optical power.
• Improved coherence length by 10%, with experimental data aligning well with simulations.

Conclusions:

• Frequency selective feedback is an effective method for optimizing QD-SLD spectra for low coherent light interferometry.
• The technique successfully reduces spectral dips, enhancing coherence properties and image quality.
• Simulations suggest potential for further improvements in QD-SLD performance.