Apparatus and methods for facilitating calibration of an optical instrument
View Patent ↗An optical system comprising an optical instrument and a processing unit. The optical instrument may comprise an illumination source and a sensor. The processing unit may comprise a data storage having stored thereon a characterization of the illumination source and a characterization of the sensor. The processing unit may also comprise a computer configured to calculate a system response of the illumination source and the receiving element considering the characterization of the illumination source and the characterization of the receiving element.
1. An optical instrument comprising:
a. illumination optics including one or more illumination sources;
b. receiving optics including one or more sensors adapted to receive light from the illumination optics; and
c. a processing unit having data storage means, the processing unit also including:
i. means for characterizing a system response for the optical instrument;
ii. means for determining one or more temperatures of the one or more illumination sources based on optical criteria detected by the receiving optics;
iii. means for refining the characterization of the system response based on determination of the one or more temperatures.
2. The optical instrument of claim 1 , wherein the means for characterizing a system response includes:
a. means for characterizing the one or more illumination sources;
b. means for characterizing the one or more sensors;
c. means for determining a response for each spectral channel of the optical instrument; and
d. means for normalizing the illumination optics and the receiving optics to white and black standards.
3. The optical instrument of claim 1 , wherein the means for determining one or more temperatures includes adaptation of the one or more sensors to detect a spectral shift of one or more of the one or more illumination sources.
4. The optical instrument of claim 2 , wherein the means for characterizing the one or more illumination sources is adapted to:
a. detect at least one optical criteria selected from the group consisting of: spectral output, spectral optical power, spectral optical linearity, degree of collimation, illuminated spot size, spot intensity profile, illumination uniformity, spatial and temporal phase, and temporal modulation; and
b. use the detected optical criteria to select at least one model for the one or more illumination sources.
5. The optical instrument of claim 3 , further comprising one or more spectral filters positioned on or near one or more of the one or more sensors and defining one or more active areas, wherein the one or more active areas are adapted to detect the spectral shift.
6. The optical instrument of claim 2 , wherein the means for characterizing the one or more sensors is adapted to:
a. detect at least one optical criterion selected from the group consisting of spectral responsivity, spatial responsivity, temporal responsivity, field of view, degree of specular rejection, degree of stray light rejection and dynamic range of response; and
b. use the detected at least one optical criterion to select at least one model for the one or more sensors.
7. A method of operating an optical instrument, the optical instrument comprising illumination optics including one or more illumination sources, and receiving optics including one or more sensors adapted to receive light from the illumination optics, the method comprising:
a. characterizing a system response for the optical instrument;
b. determining one or more temperatures of the one or more illumination sources, based on optical criteria detected by the receiving optics; and
c. refining the characterization of the system response based on the one or more temperatures.
8. The method of claim 7 , further comprising:
a. performing a measurement with the optical instrument; and
b. normalizing the measurement based on the refined characterization of the system response.
9. The method of claim 7 , wherein the step of characterizing a system response includes:
a. characterizing the one or more illumination sources;
b. characterizing the one or more sensors;
c. determining a response for each spectral channel of the optical instrument; and
d. normalizing the illumination optics and the receiving optics to white and black standards.
10. The method of claim 7 , wherein the step of determining one or more temperatures includes using one or more of the one or more sensors to detect a spectral shift of one or more of the one or more illumination sources.
11. The method of claim 10 , wherein the optical instrument further comprises one or more spectral filters positioned on or near one or more of the one or more sensors and defining one or more active areas, wherein the one or more active areas are used to detect the spectral shift.
12. The method of claim 9 , wherein the determining a response for each spectral channel includes mathematically combining an optical criterion of one of the illumination sources with a corresponding optical criterion of an active area of the one or more sensors, wherein the mathematically combining comprises at least-one of the group consisting of taking a convolution, taking a vector sum, and taking an arithmetic sum.
13. A method for characterizing a system response for an optical instrument, the optical instrument comprising illumination optics including one or more illumination sources and receiving optics including one or more sensors, the method comprising:
a. characterizing the one or more illumination sources;
b. characterizing the one or more sensors;
c. determining a response for each spectral channel of the optical instrument; and
d. normalizing the illumination optics and the receiving optics to white and black standards.
14. The method of claim 13 , wherein the characterizing of the one or more illumination sources comprises:
a. detecting at least one optical criterion of one or more of the one or more illumination sources over a first range of operating conditions; and
b. using the detected at least one optical criterion to select at least one model for the one or more illumination sources.
15. The method of claim 14 , wherein the at least one optical criterion is selected from the group consisting of: spectral output, spectral optical power, spectral optical linearity, degree of collimation, illuminated spot size, spot intensity profile, illumination uniformity, spatial and temporal phase, and temporal modulation.
16. The method of claim 14 , wherein the detection of at least one optical criterion over a first range of operating conditions comprises illuminating one or more of the one or more illumination sources over a period of time; and accounting for changes in temperature over the period of time.
17. The method of claim 13 , wherein the determining a response for each spectral channel includes mathematically combining an optical criterion of one of the illumination sources with a corresponding optical criterion of an active area of the one or more sensors, wherein the mathematically combining comprises at least-one of the group consisting of taking a convolution, taking a vector sum, and taking an arithmetic sum.
18. The method of claim 13 , wherein the characterization of the one or more sensors includes:
a. detecting at least one optical criterion of one or more active areas of the one or more sensors; and
b. using the detected at least one criterion to select at least one model for the one or more sensors.
19. The method of claim 18 , wherein the at least one optical criterion is selected from the group consisting of spectral responsivity, spatial responsivity, temporal responsivity, field of view, degree of specular rejection, degree of stray light rejection and dynamic range of response.
20. The method of claim 13 , wherein the response for each spectral channel is normalized to a colorspace.