Optical measurement system

Patent metadata

Field	Value
Publication number	US-2021149337-A1
Application number	US-202017028012-A
Country	US
Kind code	A1
Filing date	Sep 22, 2020
Priority date	Nov 14, 2019
Publication date	May 20, 2021
Grant date	—

Abstract

An optical measurement system comprises a polarization beam splitter for dividing an incident beam into a reference beam and a measurement beam, a first beam splitter for reflecting the measurement beam to form a first reflected measurement beam, a spatial light modulator for modulating the first reflected measurement beam to form a modulated measurement beam, a condenser lens for focusing the modulated measurement beam to an object to form a penetrating measurement beam, an objective lens for converting the penetrating measurement beam into a parallel measurement beam, a mirror for reflecting the parallel measurement beam to form an object beam, a second beam splitter for reflecting the reference beam to a path coincident with that of the object beam, and a camera for receiving an interference signal generated by the reference beam and the object beam to generate an image of the object.

First claim

What is claimed is:

1 . An optical measurement system, comprising:
a polarization beam splitter, dividing an incident beam into a reference beam and an original measurement beam; a first beam splitter, receiving the original measurement beam and reflecting the original measurement beam to form a first reflected measurement beam; a spatial light modulator, receiving the first reflected measurement beam and modulating a reflection direction of the first reflected measurement beam to form a modulated measurement beam; a condenser lens, receiving the modulated measurement and focusing the modulated measurement beam to an object to be measured, wherein the modulated measurement beam penetrates the object to be measured to form a penetrating measurement beam; an objective lens, receiving the penetrating measurement beam and converting the penetrating measurement beam into a parallel measurement beam; a mirror, receiving the parallel measurement beam and reflecting the parallel measurement beam to form a second reflected measurement beam; a second beam splitter, receiving the reference beam and reflecting the reference beam to a path coincident with a path of the second reflected measurement beam, wherein the reference beam interferes with the second reflected measurement beam to generate an interference signal; and a camera, receiving the interference signal to generate an original image, wherein the original image comprises a phase distribution image having surface topography representative of the object to be measured.

2 . The optical measurement system according to claim 1 , further comprising a processing device, wherein the processing device is connected with the camera, obtains the phase distribution image using a field retrieval algorithm, and obtains a three-dimensional image of refractive index distribution of the object to be measured using information represented by the phase distribution image.

3 . The optical measurement system according to claim 2 , wherein the information presented by the phase distribution image and the three-dimensional image satisfy an equation, wherein the equation is:

U
Rytov



(

f
x

,

f
y

,

z
+

=
0

)

=

1

j



4



π



fz



(

F
x

,

F
y

,

F
z

)

;

wherein U Rytov (f x , f y , z + =0) represents the three-dimensional image, and (F x , F y , F z )
represents the information represented by the phase distribution image.

4 . The optical measurement system according to claim 2 , wherein the processing device comprises a classifier performing a classification procedure, and the classification procedure comprises:
obtaining three-dimensional images of samples, wherein the three-dimensional images respectively represent refractive index distribution of the samples; obtaining pieces of reference original data respectively from the three-dimensional images, wherein each of the pieces of reference original data represents structural features and biochemical characteristics of a corresponding one of the samples; dividing the pieces of reference original data into a training data set and a test data set; training the training data set; establishing a reference classification model by combining feature subsets extracted from the training data set; choosing a best classification model from the reference classification model; and applying the best classification model for determining a type of the object to be measured.

5 . The optical measurement system according to claim 4 , wherein the step of obtaining the pieces of reference original data in the classification procedure comprises:
according to voxel data of each of the three-dimensional images, obtaining a surface area and a volume of a corresponding one of the samples to represent the structural features; and based on local concentration of non-aqueous molecules of the samples, determining protein density and dry mass of each of the samples to represent the biochemical characteristics.

6 . The optical measurement system according to claim 5 , wherein the step of obtaining the pieces of reference original data in the classification procedure further comprises:
determining sphericity of each of the samples by a ratio of the volume to the surface area when the samples are substantially spherical.

7 . The optical measurement system according to claim 2 , wherein the processing device comprises a classifier performing a classification procedure, and the classification procedure comprises:
obtaining three-dimensional images of samples, wherein the three-dimensional images respectively represent refractive index distribution of the samples; obtaining pieces of reference original data respectively from the three-dimensional images, wherein each of the pieces of reference original data represents structural features of a corresponding one of the samples; dividing the pieces of reference original data into a training data set and a test data set; training the training data set; establishing a reference classification model by combining feature subsets extracted from the training data set; choosing a best classification model from the reference classification model; and applying the best classification model for determining a type of the object to be measured.

8 . The optical measurement system according to claim 7 , wherein the step of obtaining the pieces of reference original data in the classification procedure comprises:
according to voxel data of each of the three-dimensional images, obtaining a surface area and a volume of a corresponding one of the samples to represent the structural features.

9 . The optical measurement system according to claim 4 , wherein the step of training the training data set in the classification procedure performed by the classifier is

Assignees

• Ind Tech Res Inst

Inventors

• Wei Hsiang-Chun
• Kuo Chung-Lun
• Cho Chia-Hung
• Lo Chun-Wei
• Liu Chih-Hsiang

Classifications

• G03H1/0443 Primary

  Digital holography, i.e. recording holograms with digital recording means (holobject computation G03H1/0866) · CPC title

• G01B9/02024 Primary

  Measuring in transmission, i.e. light traverses the object · CPC title

• G06V20/693

  Acquisition · CPC title

• G06V20/64

  Three-dimensional [3D] objects · CPC title

• G06V10/145

  Illumination specially adapted for pattern recognition, e.g. using gratings · CPC title