Abstract: An apparatus for measuring specular reflectance of a sample is provided including a light source for transmitting a beam of light at an angle of incidence onto a surface of a sample; a polarizing filter comprising a wire grid that avoids a need for collimation of the incident beam of light; a sample holder for mounting the sample; and a detector assembly for detecting a beam of light which is specularly reflected from a surface of the sample; wherein the sample holder and detector assembly are mounted for relative movement, such that the light source, the detector assembly and the sample holder are relatively positionable for a specularly reflected component of a transmitted light beam to be detected for different angles of incidence of the light beam.

Abstract: In some embodiments, the pathlength difference (retardation) in a step scanning infrared (IR) spectrometer interferometer is maintained under AC servomechanism (servo) control for a first period following a step change, and under DC servo control for a second period following the first period. Data is acquired during and/or after the DC servo control period. Switching off the AC servo control prior to data acquisition allows limiting the dither-frequency noise that could otherwise affect signals of interest, particularly in fast-time-scale applications such as high-speed time-resolved spectroscopy (TSR). A mirror position control circuit controls a mirror position stepping as well as switching a mirror servo control from AC to DC.

Abstract: A pulsable light source for a spectroscopy instrument is provided, the light source including a xenon flash lamp having an anode and a cathode within a sealed envelope of pressurized xenon gas, the anode and the cathode being spaced so that an arc can be struck between the anode and the cathode without the use of a trigger electrode.

Abstract: An apparatus for measuring specular reflectance of a sample is provided including a light source for transmitting a beam of light at an angle of incidence onto a surface of a sample; a polarising filter comprising a wire grid that avoids a need for collimation of the incident beam of light; a sample holder for mounting the sample; and a detector assembly for detecting a beam of light which is specularly reflected from a surface of the sample; wherein the sample holder and detector assembly are mounted for relative movement, such that the light source, the detector assembly and the sample holder are relatively positionable for a specularly reflected component of a transmitted light beam to be detected for different angles of incidence of the light beam.