Session Index

In this talk, I will present how to construct a freeform lens to make the beam with Gaussian profile into an optical distribution with rotation-symmetric user-defined profile and collimated simultaneously. In general, a beam shaping system requires two surfaces to make the output profile with uniform and collimated at the same time. One surface is responsible for the uniformity, the other one is to make the ray collimation but keep uniform. However, it is possible to convert an incoherence Gaussian beam with divergence into uniform and collimated by using only one a Fresnel surface that will be discussed in this talk. When a beam shaping profile of some applications is not uniform irradiance, it could be difficult to devise an optical system to make the beam with a desirable optical distribution and collimation simultaneously. A numerical method is a way to deduce a freeform lens for leading a collimated rotation symmetric beam profile. Two user-defined profiles (that is, triangle-like and ring distributions) are shown in this talk. The simulation results show that the triangle-like distribution has a great approximation for the ideal case. Although the original simulation of the ring distribution is different from the ideal case, the triangle-like distribution is applied to modify for the ring profile improvement. As a result, the proposed method is more flexible to devise the freeform lens of the specific distribution to conduct the desirable beam shaping profile.

 

We study the absorption characteristics of CO2 gas in infrared region and the mechanism behind non-dispersive infrared measurement. Based on the layer structure of distributed bragg reflection, we design a narrow-band filter that matches spectrally to the absorption region of carbon dioxide to enhance the sensitivity of the gas sensor.

 

A unique configuration of differential interference contrast (DIC) microscopy, which employs a modified Michelson module to not only adjust the relative phase-shift but also flexibly control the shear displacement, is presented. The proposed dual-mode can significantly extends the limited measuring range of the phase-shifting microscopes from nanoscale to the microscale

 

In this paper, we develop an image processing algorithm to capture a curved image. This method can be applied to simplify the design of a wide-angle lens.

 

This article was designed for three pieces of lens of cell phone lens and analyzed the thickness of the camera lens. It is expected that the length from the first surface of the lens to the image plane is within 2 mm, and the resolution can reach 2 million pixels.