Appendix A Lens Calibration Adjustments
A.1 Plano convex Lens Calibration
When a lens is used at a wavelength different from the calibrated wavelength, a correction needs to be made.
Equation 15 provides the formula for calculating the new focal length. Do not apply these equations to
achromatic lenses.
Where:
The measured focal length of the lens at the calibration wavelength
The calculated focal length of the lens at the desired wavelength
The index of refraction of the lens substrate at the calibration wavelength
The index of refraction of the lens substrate at the desired wavelength, λ
Section A.2 provides index of refraction values for common lens materials at various wavelengths.
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