CN-121994756-A - System for testing absorptivity of glass wafer

CN121994756ACN 121994756 ACN121994756 ACN 121994756ACN-121994756-A

Abstract

The application discloses a system for testing the absorptivity of a glass wafer, which comprises the glass wafer to be tested, a coupling-in element, a first coupling-out element and a second coupling-out element which are arranged on the glass wafer to be tested, wherein the distances between the first coupling-out element and the second coupling-out element and the coupling-in element are different, after light is coupled into the glass wafer to be tested from the coupling-in element, the coupling-in energy of the light transmitted towards the first coupling-out element is the same as the coupling-in energy of the light transmitted towards the second coupling-out element, and the coupling-out efficiency of the first coupling-out element and the second coupling-out element is the same so as to obtain the absorptivity of the glass wafer to be tested according to the coupling-out energy difference of the first coupling-out element and the second coupling-out element and the optical path difference of the light transmitted towards the first coupling-out element and the second coupling-out element respectively. The technical scheme provided by the application can improve the test accuracy of the absorptivity of the glass wafer.

Inventors

HUANG HE
LOU XINYE
ZHANG YAQIN

Assignees

上海鲲游科技有限公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (10)

1. A system for testing the absorptivity of a glass wafer, said system comprising: The device comprises a glass wafer to be tested, a coupling-in element, a first coupling-out element and a second coupling-out element, wherein the coupling-in element, the first coupling-out element and the second coupling-out element are arranged on the glass wafer to be tested, and the distances between the first coupling-out element and the second coupling-out element and the coupling-in element are different; After the light is coupled into the glass wafer to be tested from the coupling-in element, the coupling-in energy of the light propagating towards the first coupling-out element is the same as the coupling-in energy of the light propagating towards the second coupling-out element, and the coupling-out efficiencies of the first coupling-out element and the second coupling-out element are the same so as to obtain the absorptivity of the glass wafer to be tested according to the coupling-out energy difference between the first coupling-out element and the second coupling-out element and the optical path difference of the light propagating towards the first coupling-out element and the second coupling-out element respectively.
2. The test system of claim 1, wherein the in-coupling element, the first out-coupling element, and the second out-coupling element are diffractive optical elements, wherein the in-coupling element is a symmetrical tooth grating, and wherein the tooth profile of the first out-coupling element and the second out-coupling element are symmetrical about the in-coupling element.
3. The test system of claim 2, wherein the grating periods of the in-coupling element, the first out-coupling element, and the second out-coupling element are the same and range from 250nm to 500nm.
4. The test system of claim 2, wherein the first and second out-coupling elements are symmetrically toothed gratings of identical structure or the first and second out-coupling elements are asymmetrically toothed with respect to the in-coupling element.
5. The test system of claim 2, wherein the in-coupling element, the first out-coupling element, and the second out-coupling element are disposed on an auxiliary substrate that is removably coupled to the glass wafer under test, and wherein light is coupled into the auxiliary substrate for total internal reflection transmission within the auxiliary substrate, the glass wafer under test, and the connection elements between the auxiliary substrate and the glass wafer under test.
6. The test system of claim 1, wherein the in-coupling element, the first out-coupling element, and the second out-coupling element are all geometric optical elements.
7. The test system of claim 6, wherein the coupling-in element is located between the first coupling-out element and the second coupling-out element, the coupling-in element includes a first coupling-in surface and a second coupling-in surface, light coupled in from the first coupling-in surface propagates toward the first coupling-out element, light coupled in from the second coupling-in surface propagates toward the second coupling-out element, and the energy of light coupled in from the first coupling-in surface and the second coupling-in surface, respectively, is the same.
8. The test system of claim 7, wherein the in-coupling element, the first out-coupling element, and the second out-coupling element are not located on a same line.
9. The test system of claim 6, wherein the first and second out-coupling elements are the same prism, the prism being implemented as the first out-coupling element when the prism is a first dimension from the in-coupling element, and the prism being implemented as the second out-coupling element when the prism is a second dimension from the in-coupling element, wherein the in-coupling element, the first out-coupling element, and the second out-coupling element are on the same straight line.
10. The test system of any one of claims 1-9, wherein the absorbance a of the glass wafer under test is: Out2 is the coupling-Out energy of the second coupling-Out element, out1 is the coupling-Out energy of the first coupling-Out element, α 2 is the total reflection angle of the light propagating towards the second coupling-Out element at the glass wafer to be measured, α 1 is the total reflection angle of the light propagating towards the second coupling-Out element at the glass wafer to be measured, D2 is the relative lateral distance between the second coupling-Out element and the coupling-in element, and D1 is the relative lateral distance between the first coupling-Out element and the coupling-in element.

Description

System for testing absorptivity of glass wafer Technical Field The application relates to the field of augmented reality, in particular to a system for testing the absorptivity of a glass wafer. Background Augmented reality is a technology that merges real world and virtual information, and an augmented reality display system typically includes a micro projector and an optical display screen, where the micro projector provides virtual display content for the augmented reality display system to be projected into the human eye through the optical display screen, which is typically a transparent optical component, so that a user can see the real world through the optical display screen at the same time. In designing a diffractive optical waveguide, it is generally necessary to know the absorptivity of a glass wafer used as a waveguide substrate, and conventional absorptivity test methods are required to test the transmittance and reflectance of the glass wafer in a near normal incidence state, respectively, but in such a manner, in the case where the glass wafer is too thin, the test is very inaccurate due to the too low absorptivity itself. Disclosure of Invention The embodiment of the application provides a system for testing the absorptivity of a glass wafer, which can improve the testing accuracy of the absorptivity of the glass wafer by prolonging the absorption light path of light. A system for testing the absorptivity of a glass wafer, the system comprising: The device comprises a glass wafer to be tested, a coupling-in element, a first coupling-out element and a second coupling-out element, wherein the coupling-in element, the first coupling-out element and the second coupling-out element are arranged on the glass wafer to be tested, and the distances between the first coupling-out element and the second coupling-out element and the coupling-in element are different; After the light is coupled into the glass wafer to be tested from the coupling-in element, the coupling-in energy of the light propagating towards the first coupling-out element is the same as the coupling-in energy of the light propagating towards the second coupling-out element, and the coupling-out efficiencies of the first coupling-out element and the second coupling-out element are the same so as to obtain the absorptivity of the glass wafer to be tested according to the coupling-out energy difference between the first coupling-out element and the second coupling-out element and the optical path difference of the light propagating towards the first coupling-out element and the second coupling-out element respectively. The coupling-in element, the first coupling-out element and the second coupling-out element are all diffraction optical elements, wherein the coupling-in element is a symmetrical tooth-shaped grating, and tooth shapes of the first coupling-out element and the second coupling-out element are symmetrical relative to the coupling-in element. In one embodiment, the grating period of the coupling-in element, the first coupling-out element and the second coupling-out element is identical and ranges from 250nm to 500nm. In an embodiment, the first and second coupling-out elements are symmetrically toothed gratings of identical structure, or the first and second coupling-out elements are asymmetrically toothed with respect to the coupling-in element. In one embodiment, the coupling-in element, the first coupling-out element and the second coupling-out element are disposed on an auxiliary substrate, the auxiliary substrate is removably connected to the glass wafer to be tested, and the light is transmitted in a total internal reflection manner after being coupled into the auxiliary substrate, the glass wafer to be tested and the connection element between the auxiliary substrate and the glass wafer to be tested. In one embodiment, the coupling-in element, the first coupling-out element and the second coupling-out element are geometrical optical elements. In one embodiment, the coupling-in element is located between the first coupling-out element and the second coupling-out element, the coupling-in element includes a first coupling-in surface and a second coupling-in surface, the light coupled from the first coupling-in surface propagates toward the first coupling-out element, the light coupled from the second coupling-in surface propagates toward the second coupling-out element, and the energy of the light coupled from the first coupling-in surface and the second coupling-in surface is the same. In one embodiment, the coupling-in element, the first coupling-out element and the second coupling-out element are not located on the same line. In one embodiment, the first coupling-out element and the second coupling-out element are identical prisms, the prisms are implemented as the first coupling-out element when the prisms are at a first size from the coupling-in element, and the prisms are implemented as the second coupling-out elem