Prototypical Simulation of an Optical Edge Filter Design for Three Different Rayleigh Wavelengths Using Octave Software

Optical filters used specifically for special functions to block a particular wavelength or range of wavelength and transmit the rest of the spectrum have received research attention for the past few eras. Recently, optical filter based on multilayer coating are more focused due to potential to manipulate filter properties by changing layer thickness in order to apply in various fields. This Quarter wave stack (QWS) model design is one of the approaches to design optical filter such as edge filter. However, to obtain desire minimum specification need an optimization. Therefore, in this study aims to design optical edge filter based QWS model by optical matrix method in Octave software. In this design, MoS2 and Si are being choose for high (H) and low (L) refractive index materials respectively. The optimum twenty-four (24) number of layers are determined by calculating maximum transmittance obtained. The Rayleigh wavelength ( λex ) of 405 nm ,532 nm and 633 nm are selected and ‘glass|12HL|air’ configuration is set for the design simulation.  Then, the cut-on wavelength (λcut-on) and cut-off wavelength ((λcut-off) of successful designed optical edge filter are measured. The result shows that the cut-on wavelength of 408.11 nm, 536 nm and 640.25 nm with minimum effective transmission (MET) of 32.3%, 31.3% and 32% respectively are obtained. In conclusion, this present study shows the deviation between the calculated value and simulation of about 0.2 nm,1.7 nm and 1.15 nm for each λex of 405 nm, 532 nm and 633 nm is determined.  But for λcut-off, the value obtained are much higher than the calculated value. The MET of each filter is 32.3% ,31.3% and 32% for Rayleigh wavelength respectively.