Pure adaptive interferometer for free form surfaces metrology

Abstract

A pure adaptive interferometer is proposed for optical free form surfaces metrology without auxiliary devices such as the wavefont sensors and deflectometry systems for DM monitoring. In this method, the DM surface monitoring and free form surface measurement are achieved simultaneously in only one interferometer. The polarizing optics divide the interferometer into two partial common path interferometric system, which provide the null test for tested free form surface and non-null test for the DM surface. The final figure error of the free form surface is extracted by ray tracing. Experiments proving the feasibility of this interferometer is shown.

Freeform surface adaptive interferometry assisted with simulated annealing-hill climbing algorithm

“…11(c). Of course, the DM was calibrated in advance as described in [16]. Then the system model was set up for ray tracing, with the resulting null As is shown in Fig.…”

“…Several dynamic compensators have been developed, in which adaptive optics, such as the deformable mirror (DM) and liquid crystal spatial light modulator (LC-SLM), have the most prominent performance. The freeform surface adaptive interferometer (FSAI) thus has been proposed [14][15][16][17][18][19][20][21][22][23] based on the DM and LC-SLM, aiming to perform adaptive aberration correction to realize the near null test in testing freeform surfaces with various shapes. The near null fringes would be acquired from the initial interferogram with the implementation of the adaptive compensation algorithm.…”

Measurement of Freeform Optical Surfaces: Trade‐Off between Accuracy and Dynamic Range

“…To overcome this problem, Zhang et al. [ 118 ] proposed a DM‐based adaptive freeform surface interferometer divided into two subsystems. One is the adaptive null test comprising the conventional null or partial null optics and the DM as shown in Figure 13b.…”

An Improved Method for NURBS Free-Form Surface Based on Discrete Stationary Wavelet Transform

“…Then, the largest rectangle or square is acquired according to boundary size. Finally, smaller rectangles or squares are classified along the X axis-direction and Y axis-direction, as shown in (1)- (2). Suppose the length and width of rectangle or square are Q x and Q y .…”

“…With the development of modern industry, construction of complex free-form surface model has been widely used in reverse engineering in recent years [1], [2]. High precision fitting of the free-form surface is an important technique for the reverse engineering and the machinery parts processing industry, and the precision level of fitting directly determines the quality of the product.…”