Abstract

The attenuation of incoherent infrared radiation for wavelengths from 6 to 20 μm was investigated for hollow sapphire and silica waveguides suitable for applications in spectroscopy and thermometry. A low-attenuation region was exhibited between 9.6 and 17.2 μm for hollow sapphire fibers and between 7.25 and 9.5 μm for hollow silica fibers as a result of the cladding index of refraction dipping below that of the air core (n ≈ 1). Losses have been characterized as a function of fiber diameter, launch conditions, and waveguide bend radius for cladding regions of both n > 1 and n < 1. In addition, the remote infrared sensing capability of the hollow waveguides was demonstrated by the detection of CO₂ in N₂ by utilizing hollow sapphire fibers capped with ZnSe windows.

© 1991 Optical Society of America

Hollow sapphire fibers for the delivery of CO₂ laser energy

James A. Harrington and Christopher C. Gregory
Opt. Lett. 15(10) 541-543 (1990)

Hollow glass waveguides for broadband infrared transmission

Todd Abel, Jeff Hirsch, and James A. Harrington
Opt. Lett. 19(14) 1034-1036 (1994)

Preparation and transmission characteristics of a mid-infrared attenuated total reflection hollow waveguide based on a stainless steel capillary tube

Xu Wang, Hong Guo, Lin Wang, Fangyu Yue, Chengbin Jing, and Junhao Chu
Appl. Opt. 55(23) 6404-6409 (2016)

Attenuation, modal, and polarization properties of n < 1, hollow dielectric waveguides

Christopher C. Gregory and James A. Harrington
Appl. Opt. 32(27) 5302-5309 (1993)

Small-bore hollow waveguides for delivery of 3-μm laser radiation

Rebecca L. Kozodoy, Antonio T. Pagkalinawan, and James A. Harrington
Appl. Opt. 35(7) 1077-1082 (1996)