System and method for laser temperature compensation
AssigneeFinesse Solutions, Inc.
InventorsAlfred Riddle, John Havard
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Abstract
A method for compensating for changes in output power or wavelength of an optical source with temperature. Many optical sources have power and/or wavelength variations with temperature which can be compensated by open- or closed-loop methods if a method of accurately measuring the optical source temperature is available. The voltage across a semiconductor junction varies with temperature. Measuring the optical source power or wavelength variation with temperature and tracking the voltage across the semiconductor junction provides a means for compensating an instrument for temperature induced optical output power or wavelength variations. An important field of application is optical density or turbidity measurements in cellular media.
Claims6
A method for laser or LED temperature compensation using the forward voltage drop of the laser diode or LED for temperature sensing by creating the correction factor AUcorr said method comprising the steps of:
- i) determining the diode forward voltage versus temperature sensitivity of the laser or LED;
- ii) determining the optical power versus temperature sensitivity of the laser or LED;
- and
- iii) creating a compensation algorithm in accordance with the equation:
- AU
- corr
- =
- log
- 10
-
- (
- 1
- +
- Δ
-
-
- V
- fwd
-
- E
- L
- C
- L
- )
- wherein CL is the laser forward voltage change with temperature, EL is the fractional laser power degradation with temperature factor, and ΔVfwd is the relative voltage change experienced by the laser from an established reference voltage.
Dependencies are inferred from the claim text.