Laser beam wavelength determination algorithm using a digital micromirror device

An approach for wavelength characterization whereby dynamic Fresnel zone plate (FZP) patterns are written to a digital micromirror device (DMD) and used focus incoming light onto camera is proposed. The then assessed by scanning the focal length. Rectangular basis Zernike modes implemented match rectangular geometry of DMD, we believe first time. A procedure developed correct inherent aberrations optical system adjusting mode amplitudes, thus improving spot quality. aberration corrected FZPs assess focusing conditions needed four lasers different visible wavelengths ranging from blue (405 nm) near infrared (760 nm). able produce focused beams with width twice diffraction limit achieve resolution 3 nm. operational ultimately limited spectral bandwidth detector.