Princeton Docket # 08-2414
Typical optical gas sensors utilize multipass
cells to probe molecular species by absorption spectroscopy. Existing multipass cells are usually
costly, large, and lack robustness, which limits their use for portable systems.
Princeton researchers have designed
and fabricated a highly compact and robust optical cavity, which is composed of
essentially a single reflective surface formed by two quadrupolar-shaped
half-shells that are securely attached to each other. The cavity can effectively focus the beam
when light bounces repeatedly off the cavity surfaces, resulting in a negative
Liapunov exponent. This enables the
chaotic multipass cavity to be more robust against vibrations or misalignment of
the cavity shells. The cavity can
support an optical path length up to 15.5 meters with limited beam divergence in
a 68 cm3 cavity volume.
Thus, this work established a novel design principle for multipass
systems that employ a compact single surface to generate long optical
D. Qu, Z. Liu and C. Gmachl. A Compact Asymmetric Chaotic Optical
Cavity with Long Optical Path Lengths. Applied Physics Letters, vol. 93, p
D. Qu and C. Gmachl. Quasichaotic optical multipass cell. Phys. Rev. A 78, 033824 (2008).
and C. Gmachl. Modeling
and Design of a Highly Compact Chaotic Cavity for Optical Gas Sensing
Applications. Proc. IEEE Sensor.
Clair Gmachl, Eugene Higgins Professor of
Electrical Engineering and Director of MIRTHE, is the
principle inventor for these QC
laser technologies. Her
is working on the development of new
quantum devices, especially lasers, and their optimization for sensor systems
and their applications in environment and health. Among the numerous honors
Professor Gmachl has received are Election to Austrian Academy of Sciences as
Corresponding Member Abroad (2008), MacArthur Fellow (2005), and Popular Science
Magazine's list of Brilliant 10 (2004).
protection is pending.