Enhanced transmitting and blocking filter design approach for laser scanning applications based on combining GSM and AFGSM methods

Abstract

Abstract We present a design approach consisting of one-dimensional photonic crystal filters for Laser Scanning Microscopy (LSM) applications. The proposed approach based on Auxiliary Functions of Generalized Scattering Matrix (AFGSM) method provides significant flexibility in modeling desired transmission band while offering widened stop-bands. Strict spectral filter characteristics are effectively achieved by the proposed design approach without implementing commonly used complex optimization algorithms. We attest the performance of the suggested technique through designing four different filters that are commonly used in laser scanning microscopy applications; namely a laser line filter tuned to 800 nm wavelength for reflectance confocal microscopy, a bandpass filter tuned to 400 nm wavelength for second harmonic generation microscopy, a laser block filter centered to 800 nm wavelength and a dichroic filter blocking 350–400 nm while transmitting higher wavelengths for multiphoton microscopy. We demonstrate the validity and applicability of the proposed design approach considering the characteristics of the commercial optical filters.