Spectrometer with adjustable-deflector-controlled alignment for optical coherence tomography
A spectrometer is presented that can include a spectrally dispersive optical element to spectrally disperse a received light, a leveraged-optics adjustable deflector to adjustably deflect the spectrally dispersed light, and a detector array to receive the spectrally dispersed and adjustably deflected light. The received light can include an interference beam combined from a returned image beam and a reference beam in a Spectral Domain Optical Coherence Tomograph. The detector array can include a linear sensor array. The leveraged-optics adjustable deflector can include an optical element with an adjustable transmissive property or an adjustable reflective property, wherein the adjustable deflector is adjustable by a mechanical adjustment being optically leveraged into a smaller optical adjustment.
1. A spectrometer, comprising:
a spectrally dispersive optical element configured to spectrally disperse a received light;
a leveraged-optics adjustable deflector to adjustably deflect the spectrally dispersed light; and
a detector array to receive the spectrally dispersed and adjustably deflected light, wherein
the leveraged-optics adjustable deflector is configured to leverage an angle of a mechanical adjustment into an at least 10 times smaller angle of an optical adjustment.
2. The spectrometer of claim 1 , wherein:
the received light comprises an interference beam combined from a returned image beam and a reference beam.
3. The spectrometer of claim 1 , the spectrally dispersive optical element comprising at least one of:
a prism, a grating, an optical element with a wavelength dependent index of refraction, an optical element with a wavelength dependent transmission property and an optical element with a wavelength dependent deflection property.
4. The spectrometer of claim 1 , the detector array comprising at least one of:
a linear sensor array, a two-dimensional sensor array, and a detector camera.
5. The spectrometer of claim 1 , the leveraged-optics adjustable deflector comprising:
an optical element with at least one of an adjustable transmissive property and an adjustable reflective property.
6. The spectrometer of claim 1 , wherein:
a ratio of the angle of the mechanical adjustment to the angle of the optical adjustment exceeds 100.
7. The spectrometer of claim 1 , wherein:
a ratio of the angle of the mechanical adjustment to the angle of the optical adjustment is more than 5 and less than 100.
8. The spectrometer of claim 1 , the adjustable deflector comprising:
at least one rotatable wedged optical plate.
9. The spectrometer of claim 1 , wherein:
the spectrometer is an imaging spectrometer, comprising
a collimator, converting the received light into a parallel light; and
a focusing lens, focusing and imaging the spectrally dispersed light onto the detector array.
10. The spectrometer of claim 1 , wherein:
a first detector-beam-position range associated with a deflection-adjustment range of the deflector exceeds a second detector-beam-position range associated with a cumulative position-tolerance range of components of the spectrometer.
11. The spectrometer of claim 1 , wherein:
a first detector-beam-position range associated with a deflection-adjustment range of the deflector exceeds an operational detector-beam-position range of the spectrometer.
12. The spectrometer of claim 1 , wherein:
an operational beam misalignment caused by the leveraged-optics adjustable deflector is smaller than a misalignment tolerance of the detector.
13. The spectrometer of claim 1 , wherein:
the adjustable deflector is configured to compensate a lateral misalignment of the spectrally dispersed light without introducing an angular misalignment larger than an aspect ratio of the detector.
14. The spectrometer of claim 1 , wherein
the spectrometer is configured to allow compensation of a longitudinal misalignment through recalibration of its sensors using a known-wavelength light.
15. A spectral domain optical coherence tomography (SD-OCT) device, comprising:
a spectral decomposer, configured
to receive an interfering light, and
to create a sheet of interfering light by laterally separating spectral components of the interfering light;
a sensor array to detect different spectral components of the sheet of interfering light by different sensors; and
a leveraged adjustable alignment-controller to control an alignment of the sheet of light with the sensor array, wherein
the leveraged adjustable alignment-controller is configured to leverage an angle of a mechanical adjustment into an at least 10 times smaller angle of an optical adjustment.
16. The SD-OCT device of claim 15 , the alignment-controller comprising:
a rotatable wedged prism.
17. A spectrometer, comprising:
a spectral disperser to laterally disperse spectral components of an image light;
a sensor array to sense the spectral components of the image light; and
an optically leveraged alignment-controller
capable of compensating a cumulative beam position misalignment due to the positional variation of elements of the spectrometer, wherein
the optically leveraged alignment-controller is configured to leverage an angle of a mechanical adjustment into an at least 10 times smaller angle of an optical adjustment.