Presentation
17 September 2018 Visible and near-IR range linear variable filter with two-dimensional modeling
Cheng-Hao (Kevin) Ko, Jih-Run Tsai, Bang-Ji Wang, Shin-Fa Lin, Chi-Tsung Hong, Wei-Huai Chiu
Author Affiliations +
Abstract
We have proposed an analytical 2D model [1] of a thickness gradient function for thin film deposition of a LVF for order sorting of a diffraction grating using an evaporation chamber. The LVF was fabricated and its thickness profile was measured using a probe-type surface analyzer. This study proposes an innovative method for overcoming the low production rates currently associated with LVF fabrication.

Within the 25% - 75% thickness range, the profile distribution exhibits a high degree of linearity, with R2 are greater than or equal to 0.9914 for both the cases. The LVF zone width appears to be a linear function of the mask height h, with R2 are greater than or equal to 0.9982 for all the cases. This indicates that the thickness gradient function is a more accurate model for obtaining the thickness profile of an LVF than any other modeling mentioned in previous published results. This study demonstrates that the developed theoretical 2D model can be used to predict accurately the thin film profile of an LVF.

The effective zone width of the LVF is defined as a thickness range of 25% - 75%, which appears to have high degree of linearity as a function of the mask height, h (mask-to-substrate gap). Thus, these results also confirms that the linear variable area increases as the mask-to-substrate gap increases. Thin film layer structures are constructed to demonstrate the efficacy of the proposed LVF design concept. Transmission spectrum result (wavebands 400nm to 1000nm) for varying mask heights at different positions shows maximum number of wavebands with transmittance (>99.9%). Comparison of both the theoretical and the evaporating results matches satisfactorily.
Conference Presentation
© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Cheng-Hao (Kevin) Ko, Jih-Run Tsai, Bang-Ji Wang, Shin-Fa Lin, Chi-Tsung Hong, and Wei-Huai Chiu "Visible and near-IR range linear variable filter with two-dimensional modeling", Proc. SPIE 10746, Novel Optical Systems Design and Optimization XXI, 1074607 (17 September 2018); https://doi.org/10.1117/12.2322049
Advertisement
Advertisement
KEYWORDS
Medicine

Microelectromechanical systems

Near infrared

Safety

Visible radiation

Diffraction

Sensors

Back to Top