Pulse width modulation of continuum sources for determination of chemical composition

摘要

A light source and a method for its use in an optical sensor are provided, the light source including a resistively heated element. The light source includes a power circuit configured to provide a pulse width modulated voltage to the resistively heated element, the pulse width modulated voltage including: a duty cycle with a first voltage; and a pulse period including a period with a second voltage, wherein: the duty cycle, the first voltage, and the pulse period are selected so that the resistively heated element is heated to a first temperature; and the first temperature is selected to emit black body radiation in a continuum spectral range. Also provided is an optical sensor for determining a chemical composition including a light source as above.

主权项

1. An optical sensor for determining a chemical composition of a sample, the optical sensor comprising:
a light source comprising a resistively heated element; a power circuit configured to provide a pulse width modulated voltage signal to the resistively heated element to heat the resistively heated element to a temperature selected to emit black body radiation in a continuum spectral range; an optical delivery system to direct an illumination light to a sample; a sample cavity containing the sample and configured to receive the illumination light; an optical collection system to collect a sample light; and a detector synchronized to the pulse width modulated voltage signal, the detector configured to measure the sample light from the optical collection system.