SINGLE-MODE INFRARED LIGHT GUIDE WITH LARGE FIELD DIAMETER Russian patent published in 2025 - IPC G02B6/14 

FIELD: measuring.

SUBSTANCE: invention relates to single-mode infrared light guides intended for obtaining information on temperature of a biological object in the temperature range of 20-50 °C in medical fibre thermal imagers and pyrometers. Light guide operates in the wavelength range of 8.9-9.9 mcm in a single-mode mode with a large mode field diameter; the fibres are based on monocrystals of the AgBr-AgI system. Light guide presented in the drawing with an example of radiation distribution at wavelength of 9.2 mcm (temperature of 42 °C) transmits up to 70 % of infrared radiation with a mode field diameter of 290±5 mcm due to chemical composition and structure of light guide with outer diameter of cladding D = 1.15±0.05 mm, in which there is a core formed by two rings of rods with diameter MFD = 300.0±10.0 mcm with central rod with diameter of 19.0±1.0 mcm and shell rods of the same diameter, arranged in hexagonal order at a distance between their centres Δ = 150.0±5.0 mcm.

EFFECT: obtaining a light guide with durability, safety and high accuracy of controlling temperature of biological objects in range of 20-50 °C.

1 cl, 1 dwg