Acta Optica Sinica, Volume. 38, Issue 7, 0724002(2018)
Simulation and Experiment of Grooved Grating Microstructure for Infrared Chromatic Aberration Correction
For traditional optical components, there are some issues in chromatic aberration correction of infrared bands, such as complexity of system structure, great loss of light energy, large mass and so on. Taking the chromatic aberration of 4.8 μm and 10.6 μm infrared wavebands as an example, we study the chromatic aberration correction in the infrared band with the grooved grating surface microstructure. According to the generalized Snell law and the theory of finite difference time domain (FDTD), the surface phase distributions of the microstructures are calculated. The double square cylinders grooved grating microstructure is simulated with FDTD Solution software. The widths of the grooved grating microstructure are designed to be L1=400 nm and L2=950 nm, and the height of the grooved grating is K=500 nm. Double square cylinders grooved grating microstructure samples are prepared by a series of other process technologies of centrifugal coating method, electron beam lithography, and ion etching. The influencing factors of photoresist thickness, exposure image quality, and etching groove type are analyzed. The results show that the phase modulation for ranges of 0 to 1.5π and 0 to 2π can be achieved under the condition of two kinds of wavelengths of 4.8 μm and 10.6 μm by changing L1 and L2. L1=408 nm, L2=944 nm, K=495.32 nm, and surface roughness is 16.32 nm, which are within the allowable range of error. The peak transmittances of two infrared bands of 4.8 μm and 10.6 μm are 71% and 64%, respectively. Using the principle of parallel light measuring longitudinal chromatic aberration, we test the longitudinal chromatic aberration of the two infrared waves reduce by 30%, which proves the effect of the grooved grating microstructure device on the chromatic aberration correction.
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Yanjun Sun, Jun Wang, Xuesong Ji, Li Wang, Yue Wang, Zhe Li. Simulation and Experiment of Grooved Grating Microstructure for Infrared Chromatic Aberration Correction[J]. Acta Optica Sinica, 2018, 38(7): 0724002
Category: Optics at Surfaces
Received: Jan. 10, 2018
Accepted: --
Published Online: Sep. 5, 2018
The Author Email: Sun Yanjun (custsun@126.com)