Mid-IR hollow fiber optics produced by Guiding Photonics are extremely useful in a range of laser delivery and spectroscopy applications including (but not limited to):
- Quantum Cascade Laser (QCL) beam delivery
- CO2 laser beam delivery for industrial and medical applications
- Mode-filtering of Mid-IR laser beams for improved beam quality
- Infrared Counter Measure (IRCM) applications
- Small volume gas cell for Mid-IR spectroscopy
- Remote delivery and signal collection for Mid-IR spectroscopy systems
- Tunable laser-based, as well as broadband, FTIR-based systems.
A sample of specific examples are given below:
University of Bari – Trace Gas Sensing
Vincenzo Spagnolo, Pietro Patimisco, Angelo Sampaolo, et. al., working at the University of Bari, Italy have developed trace gas sensors using quantum enhanced photo-acoustic spectroscopy (QEPAS) with record sensitivity. Hollow fibers from Guiding Photonics are an integral part of their systems. Single-mode hollow fibers deliver the probe QCL beam and improve the beam quality. This improvement to beam quality leads to significantly better SNR compared to using a pin-hole. Additional efforts from the Bari group, which includes a collaboration with Rice University, have further demonstrated the single-mode performance of the Guiding Photonics hollow fibers in additional studies.

V. Spagnolo, P. Patimisco, S. Borri, G. Scamarcio, B. E. Bernacki, and J. Kriesel, “Part-per-trillion level SF6 detection using a quartz enhanced photoacoustic spectroscopy-based sensor with single-mode fiber-coupled quantum cascade laser excitation,” Opt. Lett. 37, 4461-4463 (2012).
A. Sampaolo, P. Patimisco, J. M. Kriesel, F. K. Tittel, G. Scamarcio, and V. Spagnolo, “Single mode operation with mid-IR hollow fibers in the range 5.1-10.5 µm“, Optics Express 195, DOI:10.1364/OE.23.000195, (2015).
Stanford University – Combustion Diagnostics
Mitchell Spearrin, Jay Jeffries, et. al., working in Ron Hanson’s group at Stanford University, have been developing non-invasive combustion diagnostics utilizing Mid-IR absorption based spectroscopy. Hollow fibers from Guiding Photonics enable remote beam delivery of the laser beams in the harsh, high vibration environment of test facilities, such as scramjet combustors. In one set of experiments, Guiding Photonics produced a custom dual fiber probe, which enabled delivery of two separate laser sources in a common connector.

R.M. Spearrin, J.B. Jeffries, and R.K. Hanson, “Mid-infrared Absorption Sensor for Measurements of CO and CO2 in Propulsion Flows”, AIAA 2014-0390 (2014).
Princeton University / MIRTHE – Glucose Monitoring
Sabbir Liakat, et. al., working in Claire Gmachl’s group at Princeton University have developed non-invasive glucose monitoring utilizing Mid-IR spectroscopy. Hollow fibers from Guiding Photonics are an integral part of their system and have been used to both deliver the probe laser beam, as well as collect the signal. The hollow fibers not only improve the ease of use by enabling the laser source to be located remotely from the probe tip, they also improve the measurement performance. In particular, use of the fibers lead to improved SNR by mitigating the effects of vibration inherent with making measurements on live patients.

Sabbir Liakat, Kevin A. Bors, Laura Xu, Callie M. Woods, Jessica Doyle, and Claire F. Gmachl, “Noninvasive in vivo glucose sensing on human subjects using mid-infrared light,” Biomedical Optics Express, Vol. 5, Issue 7, pp. 2397-2404(2014).
Pacific Northwest National Laboratory (PNNL) – Isotope Analysis
Jim Kelly, et. al., at PNNL have developed extremely sensitive isotope analysis systems that utilize a hollow fiber as the gas cell. The hollow fiber confines the sample and guides a probe laser from a QCL source to an IR detector. The concept, called a Capillary Absorption Spectrometer (CAS), provides a near unity overlap between a sample and a tunable probe laser enabling high precision analysis of extremely small sample volumes. Guiding Photonics’s hollow fibers have significantly improved the performance of such systems and we are now working to transition this technology and develop complete systems.

J.F. Kelly, R.L. Sams, T.A. Blake, and J.M. Kriesel, “Further developments of capillary absorption spectrometers using small hollow-waveguide fibers”, SPIE Proceedings Vol. 8993, DOI: 10.1117/12.2042734 (2014).
Much of the pioneering work on hollow fiber optics (i.e., waveguides) was done by the late Jim Harrington at Rutgers University, and his book (Infrared Fibers and Their Applications) is an excellent summary of the theory, fabrication, and use.
Below is a list of additional publications describing some of the many uses of hollow fibers.
General Mid-IR Hollow Fiber:
J. M, Kriesel, N. Gat, B. E. Bernacki, R. L. Erikson, B. D. Cannon, T. L. Myers, C. M. Bledt, and J. A. Harrington, “Hollow Core Fiber Optics for Mid-Wave and Long-Wave Infrared Spectroscopy,” Proc. SPIE Vol 8018, DOI: 10.1117/12.882840 (2011).
Jason Kriesel; Nahum Gat; Bruce Bernacki; Tanya Myers; Carlos Bledt; and James Harrington; “Fiber delivery of mid-IR lasers,” (SPIE Newsroom. DOI: 10.1117/2.1201108.003794) August 2011.
C. M. Bledt, J. A. Harrington, and J. M. Kriesel, “Loss and modal properties of Ag/AgI hollow glass waveguides,” Appl. Opt. 51, 3114-3119 (2012).
R. K. Nubling, J. A. Harrington, “Launch conditions and mode coupling in hollow glass waveguides”, Opt. Eng. 37 (1998).
R. K. Nubling, J. A. Harrington, “Hollow-waveguide delivery systems for high-power, industrial CO2 lasers”, APPLIED OPTICS 34, (1996).
Single-Mode Delivery and Mode-Filtering:
J. M. Kriesel, G. M. Hagglund, N. Gat, V. Spagnolo, and P. Patimisco, “Spatial mode filtering of mid-infrared (mid-IR) laser beams with hollow core fiber optics,” SPIE Proceedings Vol. 8993, DOI: 10.1117/12.2040018 (2013).
P. Patimisco, A. Sampaolo, L. Mihai, M. Giglio, J. Kriesel, D. Sporea, G. Scamarcio, F. K. Tittel, and V. Spagnolo, “Low-Loss Coupling of Quantum Cascade Lasers into Hollow-Core Waveguides with Single-Mode Output in the 3.7–7.6 µm Spectral Range“, Sensors, 16(4), 533; doi: 10.3390/s16040533 (2016).
A. Sampaolo, P. Patimisco, J. M. Kriesel, F. K. Tittel, G. Scamarcio, and V. Spagnolo, “Single mode operation with mid-IR hollow fibers in the range 5.1-10.5 µm”, Optics Express 195, DOI:10.1364/OE.23.000195, (2015).
P. Patimisco, A. Sampaolo, M. Giglio, J. M. Kriesel, F. K. Tittel, and V. Spagnolo, “Hollow core waveguide as mid-infrared laser modal beam filter, J. Appl. Phys. 118, 113102 (2015)
Advanced Fiber Structures:
Marilena Giglio; Pietro Patimisco; Angelo Sampaolo; Jason M. Kriesel; Frank K. Tittel; Vincenzo Spagnolo, “Low-loss and single-mode tapered hollow-core waveguides optically coupled with interband and quantum cascade lasers,”, Optical Engineering, 57(1), 011004 doi:10.1117/1.OE.57.1.011004 (2017).
C.M. Bledt, J.A. Harrington, and J.M. Kriesel, “Multilayer silver / dielectric thin-film coated hollow waveguides for sensor and laser power delivery applications”, Proc. SPIE Vol. 8218, DOI: 10.1117/12.912196 (2012).
C. M. Bledt, D. V. Kopp, J. A. Harrington, S. Kino, Y. Matsuura and J. M. Kriesel, “Investigation of tapered silver / silver halide coated hollow glass waveguides for the transmission of CO2 laser radiation”, Proc. SPIE Vol. 8218, DOI: 10.1117/12.912201 (2012).
C.M. Bledt, D.V. Kopp, J.A. Harrington, and J.M. Kriesel, “Multilayer thin film coatings for reduced infrared loss in hollow glass waveguides” Proc. of SPIE Vol. 8011 80112I-1, (2011).
Sensor Use:
Nathan Li, Lei Tao, Hongming Yi, Chul Soo Kim, Mijin Kim, Chadwick L. Canedy, Charles D. Merritt, William W. Bewley, Igor Vurgaftman, Jerry R. Meyer, and Mark A. Zondlo, “Methane detection using an interband-cascade LED coupled to a hollow-core fiber“, Optics Express Vol. 29, Issue 5, pp. 7221-7231 (2021)
Jason M. Kriesel; Camille N. Makarem; Mark C. Phillips; James J. Moran; Max L. Coleman; Lance E. Christensen; James F. Kelly, “Versatile, ultra-low sample volume gas analyzer using a rapid, broad-tuning ECQCL and a hollow fiber gas cell,” Proc SPIE. 10210; doi:10.1117/12.2262612 (2017).
J.F. Kelly, R.L. Sams, T.A. Blake, and J.M. Kriesel, “Further developments of capillary absorption spectrometers using small hollow-waveguide fibers”, SPIE Proceedings Vol. 8993, DOI: 10.1117/12.2042734 (2013).
V. Spagnolo, P. Patimisco, S. Borri, G. Scamarcio, B.E. Bernacki, and J. Kriesel, “Mid-infrared fiber-coupled QCL-QEPAS sensor,” Applied Physics B, Lasers and Optics, DOI 10.1007/s00340-013-5388-3 (2013).
V. Spagnolo, P. Patimisco, S. Borri, G. Scamarcio, B. E. Bernacki, and J. Kriesel, “Part-per-trillion level SF6 detection using a quartz enhanced photoacoustic spectroscopy-based sensor with single-mode fiber-coupled quantum cascade laser excitation,” Opt. Lett. 37, 4461-4463 (2012).
Connect with one of our distributors around the world
Guiding Photonics has distributors worldwide who are familiar with our products and can assist in your purchase, if necessary. If there is no distributor in your area, or for information on our products, please contact our Sales department directly.
A & P Instrument Co., Ltd (China)
8/F,No.3, Magnolia Green Square, Lane 251, SongHuaJiang Road
Shanghai, PRC 200093
Tel: (021) 55233 800
Fax: (021) 55233 811
Email: sh@anp.com.hk
http://www.anp.com.hk
A & P Instrument Co., Ltd (Hong Kong)
Room 68,1/F Sino Industrial Plaza 9 Kai Cheung Road
Kowloon Bay, Kowloon Hong Kong
Tel: (852) 27556578
Fax: (852) 27554549
Email: info@anp.com.hk
http://www.anp.com.hk
IR System Co., ltd.
4-6-20 Atago Tama Tokyo
206-0041 Japan
Tel: +81-42-400-0373
Fax: +81-42-400-0374
Email: office@irsystem.com
https://www.irsystem.com/
Opton Laser international
Z.A. Courtabœuf
6, Avenue des Andes – Bâtiment 8
91940 Les Ulis, France
+33 1 6941 0405
contact@optonlaser.com
http://www.optonlaser.com
Photonteck Company Limited
No.8CBuilding, No.18 Jinronggang 4th Road,
East Lake Dev.Zone,
Wuhan, China
Tel: +86-27-87770930
E-mail: ethan.zhang@photonteck.com
www.photonteck.com
General Use
Q: What is the maximum fiber length?
A: For Mid-IR and VNIR fibers, maximum fiber length depends on the fiber ID:
200 µm = 1 m
300 µm = 2 m
500 µm = 5 m
750 µm = 5 m
1000 µm = 5 m
1500 µm = 5 m
For aluminum hollow core fibers (UV) the maximum fiber length is 1 meter.
The fabrication process precludes lengths longer than 5 meters (Mid-IR/VNIR) or 1 meter (UV), but multiple fibers can be butt coupled together.
Q: What are the temperature limitations of a hollow fiber cable?
A: Bare glass hollow fiber: max = 200º C
Bare plastic hollow fiber: max = 147º C max
Epoxy for connectors: -20º to 70º C
Furcation PVC: -40º C to +70º C
Q: Do hollow core fibers work for light collection?
A: Beam delivery is very efficient (> 90% transmission) with our hollow fibers, however, the collection efficiency will be relatively low unless collection optics are used.
Q: Can hollow fibers be used in a vacuum
A: Some customers have indeed successfully used our bare (no jacket) fibers for vacuum applications. Of course, since the fibers are hollow, they need to be sealed with a window at one end if you want to penetrate the vacuum chamber. We have custom flanges with windows available.
Q: Is the transmission dependent on the bend of the fiber?
A: Yes, there is additonal loss with bending the fiber which scales with radius (R) as 1/R. The linked paper that can provide additional information.
Q: Do FC/APC connectors have an advantage over an FC/PC connectors for hollow fibers?
A: No, a FC/APC (Angled Polished Cleave) is desirable for a solid core fiber, due to back-reflections caused by an index of refraction mismatch between the solid core and air. However, there is no mismatch for a hollow fiber and thus there are no-back reflections.
Ordering / Shipping
Q: Do I have to pay for shipping and handling?
A: We ask you to provide a shipping account number (e.g., DHL, Fed EX, or UPS) for the most efficient and quickest shipping possible. This also helps international shipments clear customs faster and is less expensive for you.
Q: Are Guiding product(s) subject to export control laws or restrictions?
A: No
Q: Do Guiding product(s) require any regulatory license?
A: No. Our products do not require an export license; however, it is the responsibility of the recipient to follow US Export Regulations if transferring to another party.