The present application relates to a kind of low temperature convergent transmission spectrum measuring device based on
Fourier transform infrared spectrometer.It includes
Fourier transform infrared spectrometer, convergent angle optical
system, low temperature optical
system and
receiver.Convergent angle optical
system includes collimating lens, diaphragm, convergent lens group and mirror, low temperature optical system includes window piece, sample holder and
cryostat.Using collimating lens, the divergent light of
infrared spectrometer exit is converted into parallel light, using aperture diaphragm controls parallel
light spot size, using a set of convergent lens first converts parallel light into convergent light, after the convergent light is emitted after sample exit, the emitted divergent light is converted into parallel light, using aspheric concave mirror, the incident parallel light is reflected into
receiver with convergent state, using
cryostat, the temperature of sample is reduced to the temperature to be measured.The low temperature convergent transmission spectrum measuring device has the characteristics of simple structure, convergent angle adjustable control range is large, spectral band and temperature coverage range is wide.