Mid-Infrared Optical Coherence Tomography
System using a Room Temperature Quantum
Cascade Superluminescent Emitter
Ahmed Musse, Deborah Varnell, Mei Chai Zheng, Nyan Aung, Germano Penello, and
Claire Gmachl
Department of Electrical Engineering, Princeton University, Princeton, NJ, 08644, USA
S
Motivation
S OCT systems provide us with a great imaging
technique, allowing us to create cross-sectional images
of biological tissues, similar to ultrasounds. However,
OCT systems are typically non-invasive and give
structural information within tissue.
Approach
S We decided to use a 5 μm Quantum Cascade
Superluminescent (QCSL) emitter that operates at
room temperature as our source for our OCT system.
S The device maintains low coherence providing better optical
resolution than typical QCLs that operate at low temperatures.
Design
S To create the OCT system we needed to develop a
model that represented the Michelson interferometer.
Results
S Our OCT system is capable of producing
interferograms using a movable mirror and a another
sample, in this case it is simply a gold coated mirror.
Future Work
S Future work includes testing the OCT setup with a
ZnSe window placed in the sample arm to measure the
thickness of the window.
S Eventually, biological tissue may be placed in the
sample arm and scanned to develop a cross-sectional
image.
Summary/Experience
S Aligning an IR laser can be tedious. Persistence is key!
S Gained a further understanding of Quantum Cascade
Lasers and their applications
S Gave an insight on prospective research opportunities post-
graduation
S It was great to be part of something innovative!