Abstract

We demonstrate mid-infrared photothermal interferometry (PTI) in a hollow-core fiber (HCF) for trace gas detection. Compared with free-space PTI, the optical intensity could be increased by orders of magnitude by confining the pump and probe lights in the hollow core. We coupled the pump light at 4.46 μm from a quantum cascade laser and the 1555.14 nm probe light into the HCF with a bore size of 200 μm. The HCF was filled with nitrous oxide (N2O) which has strong absorption at the pump wavelength. The probe light detects the N2O absorption-induced phase change in the HCF via a fiber-optic Mach–Zehnder interferometer. With a 25 cm fiber length and 6 mW of pump power, we have achieved a minimum detection limit of 0.8 ppm for N2O, corresponding to a normalized noise equivalent absorption coefficient of 4.9×107  cm1WHz1/2.

© 2017 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Vibrational mid-infrared photothermal spectroscopy using a fiber laser probe: asymptotic limit in signal-to-baseline contrast

Atcha Totachawattana, Hui Liu, Alket Mertiri, Mi K. Hong, Shyamsunder Erramilli, and Michelle Y. Sander
Opt. Lett. 41(1) 179-182 (2016)

Hollow-core fiber Fabry–Perot photothermal gas sensor

Fan Yang, Yanzhen Tan, Wei Jin, Yuechuan Lin, Yun Qi, and Hoi Lut Ho
Opt. Lett. 41(13) 3025-3028 (2016)

Performance optimization of hollow-core fiber photothermal gas sensors

Yuechuan Lin, Wei Jin, Fan Yang, Yanzhen Tan, and Hoi Lut Ho
Opt. Lett. 42(22) 4712-4715 (2017)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (4)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (3)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription