US-20260126325-A1 - METHOD FOR CALCULATING PHASE AND PHASE CALCULATING APPARATUS

US20260126325A1US 20260126325 A1US20260126325 A1US 20260126325A1US-20260126325-A1

Abstract

A method for calculating a phase includes irradiating a plurality of lights with different wavelengths on an optical component via a measurement target, obtaining intensity of the plurality of lights by a detector while fixing a position of the detector, the plurality of lights propagating along mutually different paths by transmitting through the optical component, and calculating a phase from the intensity of the plurality of lights.

Inventors

Takahiro Sakai

Assignees

MITSUBISHI ELECTRIC CORPORATION

Dates

Publication Date: 20260507
Application Date: 20250717
Priority Date: 20241101

Claims (9)

1 . A method for calculating a phase, the method comprising: irradiating a plurality of lights with different wavelengths on an optical component via a measurement target, obtaining intensity of the plurality of lights by a detector while fixing a position of the detector, the plurality of lights propagating along mutually different paths by transmitting through the optical component, and calculating a phase from the intensity of the plurality of lights.
2 . A method for calculating a phase according to claim 1 , wherein in the irradiating, irradiating the plurality of lights sequentially on a lens which is the optical component, and in the obtaining, the intensity of the plurality of lights having different focusing positions is obtained.
3 . A method for calculating a phase according to claim 1 , wherein in the irradiating, irradiating, simultaneously, the plurality of lights on a prism, which is the optical component, to disperse the plurality of lights, and in the obtaining, obtaining the intensity of the plurality of dispersed lights by the detector.
4 . A method for calculating a phase according to claim 1 , wherein in the irradiating, irradiating, simultaneously, the plurality of lights on a lens, which is the optical component, in the obtaining, obtaining the intensity of the plurality of lights having different focusing positions by the detector, which is a color camera.
5 . A method for calculating a phase according to claim 4 , wherein a diffraction grating is provided between the lens and the color camera, and in the obtaining, obtaining the intensity of the plurality of lights that have passed through the diffraction grating by the color camera.
6 . A method for calculating a phase according to claim 3 , wherein in the obtaining, obtaining the intensity of the plurality of lights in a single imaging by the detector.
7 . A phase calculating apparatus comprising: an optical component configured to allow incidence of a plurality of lights with different wavelengths that have passed through a measurement target, a detector configured to detect intensity of the plurality of lights propagating along mutually different paths by transmitting through the optical component, and a calculation circuit configured to calculate a phase from the intensity of the plurality of lights.
8 . A method for calculating a phase according to claim 4 , wherein in the obtaining, obtaining the intensity of the plurality of lights in a single imaging by the detector.
9 . A method for calculating a phase according to claim 5 , wherein in the obtaining, obtaining the intensity of the plurality of lights in a single imaging by the detector.

Description

BACKGROUND Field The present disclosure relates to a method for calculating a phase and a phase calculating apparatus. Background JP 2019-200080 A discloses a method for calculating a phase of a propagated light. In this method, the intensity of the propagation light is obtained in multiple types by changing the propagation distance, and a transport of intensity equation is calculated from the information of the multiple types of intensity and the propagation distance. In the method of JP 2019-200080 A, in order to obtain multiple propagation light intensity by changing the propagation distance, it is necessary to shift a detector in the direction of light travel. Therefore, there may be a need for high-precision alignment in the optical axis direction. Further, the imaging speed may be rate-limiting to the operation of the device. SUMMARY The present disclosure has been made to solve the above-mentioned problems, and aims to obtain a method for calculating a phase and a phase calculating apparatus capable of fixing the position of a detector. The features and advantages of the present disclosure may be summarized as follows. According to an aspect of the present disclosure, a method for calculating a phase includes irradiating a plurality of lights with different wavelengths on an optical component via a measurement target, obtaining intensity of the plurality of lights by a detector while fixing a position of the detector, the plurality of lights propagating along mutually different paths by transmitting through the optical component, and calculating a phase from the intensity of the plurality of lights. According to an aspect of the present disclosure, a phase calculating apparatus includes an optical component configured to allow incidence of a plurality of lights with different wavelengths that have passed through a measurement target, a detector configured to detect intensity of the plurality of lights propagating along mutually different paths by transmitting through the optical component, and a calculation circuit configured to calculate a phase from the intensity of the plurality of lights. Other and further objects, features and advantages of the disclosure will appear more fully from the following description. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram illustrating the method for calculating the phase using the transport of intensity equation. FIG. 2 is a diagram showing an example of light intensity distribution and phase distribution. FIG. 3 is a diagram illustrating the configuration of the phase calculation apparatus according to Embodiment 1. FIG. 4 is a diagram illustrating the propagation of the plurality of lights according to Embodiment 1. FIG. 5 is a flowchart showing the method for calculating the phase according to Embodiment 1. FIG. 6 is a hardware configuration diagram of the calculation circuit according to Embodiment 1. FIG. 7 is a diagram illustrating the configuration of the phase calculation apparatus according to Embodiment 2. FIG. 8 is a diagram illustrating the propagation of the plurality of lights according to Embodiment 2. FIG. 9 is a flowchart showing the method for calculating the phase according to Embodiment 2. FIG. 10 is a diagram explaining the configuration of the phase calculation apparatus according to Embodiment 3. FIG. 11 is a diagram illustrating the propagation of the plurality of lights according to Embodiment 3. FIG. 12 is a perspective view of the color filter according to Embodiment 3. FIG. 13 is a diagram illustrating the configuration of the phase calculating apparatus according to Embodiment 4. FIG. 14 is a diagram illustrating the first-order diffracted light component and the negative first-order diffracted light component detected by the detector according to Embodiment 4. DESCRIPTION OF EMBODIMENTS The method for calculating a phase and phase calculating apparatus according to each embodiment will be described with reference to the drawings. The same or corresponding components are given the same reference numerals, and repeated descriptions may be omitted. Embodiment 1 First, the Transport of Intensity Equation (TIE) will be described. The TIE is represented by the following Equation (1). [Equation⁢ 1]∇⊥2ϕz(x,y)=-kI0⁢∂ Iz(x,y)∂z(1) φz(x,y) is the phase distribution, and V, is the two-dimensional gradient operator. k is the wave number, and I0 is the intensity of the in-focus image. Iz(x,y) is the intensity distribution. In other words, the partial differential on the right side of Equation (1) represents the intensity change in the optical axis direction. Equation (2) represents the phase solution of the TIE. [Equation⁢ 2]ϕz(x,y)=IFT[14⁢π2(μ2+v2)⁢FT[kI0⁢∂ Iz(x,y)∂z]](2) FT[ . . . ] is the Fourier transform operator, and IFT[ . . . ] is the inverse Fourier transform operator. μ and v are the spatial frequencies in the x and y directions, respectively. Equation (3) is derived from the difference approximation of Equation (2). [Equation⁢