Abstract

For many infrared spectroscopic applications in the 3-5 μm spectral region, a compact, fiber optic and fiber optically pumped source of infrared radiation is needed [1]. In many cases, the ultimate detection limit of an infrared chemical sensor can be improved by increasing the optical “brightness” or radiance (in Wcm⁻²Sr⁻¹μm) of the source, and not necessarily increasing the source’s total optical power. The radiance R_bb of a black-body “glow-bar” source in the 3-5 μm region is practically limited by the source’s temperature to around R_bb ≃ 0.17 Wcm⁻²Sr⁻¹μm⁻¹ (T=1100K, λ = 4.5 μm.) Optically pumped fluorescent sources do not suffer from this limitation, and have several other important advantages over blackbody sources. These other advantages include remote location, compact size, insensitivity to electrical interference, room temperature operation, and non-reactivity with harsh or explosive environments.

© 1996 Optical Society of America