Optical sensor, optical examination device, and optical property detection method

Patent metadata

Field	Value
Publication number	US-2017179682-A1
Application number	US-201615379856-A
Country	US
Kind code	A1
Filing date	Dec 15, 2016
Priority date	Dec 22, 2015
Publication date	Jun 22, 2017
Grant date	—

Abstract

An optical sensor, an optical examination device, and a method of detecting optical properties. The optical sensor includes an irradiation system including light irradiator to irradiate a test object with light, and a detection system to detect the light that is emitted from the irradiation system to the test object and has propagated through the test object. The light irradiator includes a multilayered structure having an active layer, and the multilayered structure includes a surface-emitting laser element and a photo-sensing element optically connected to the surface-emitting laser element. The optical examination device includes the optical sensor, and a controller to calculate optical properties of the test object based on a detection result of the optical sensor. The method includes performing optical simulation to obtain a detection light quantity distribution for an optical model and performing inverse problem estimation.

First claim

What is claimed is:

1 . An optical sensor comprising:
an irradiation system including at least one light irradiator to irradiate a test object with light; and a detection system to detect the light that is emitted from the irradiation system to the test object and has propagated through the test object, wherein the light irradiator includes a multilayered structure having an active layer, the multi-layered structure including at least one surface-emitting laser element and a photo-sensing element optically connected to the at least one surface-emitting laser element.

2 . The optical sensor according to claim 1 , wherein
the at least one surface-emitting laser element and the photo-sensing element independently have mesa structure that includes the active layer.

3 . The optical sensor according to claim 2 , wherein
the mesa structure of the photo-sensing element has a slot thereon that is surrounded by an electrode.

4 . The optical sensor according to claim 2 , wherein
the multilayered structure includes a spacer layer that integrally covers bottoms of the mesa structure of the at least one surface-emitting laser element and the photo-sensing element, and the bottoms of the mesa structure are adjacent to the active layer of the mesa structure of the surface-emitting laser element and the photo-sensing element.

5 . The optical sensor according to claim 4 , wherein
the mesa structure of the photo-sensing element has a reflector on an opposite side of the spacer layer with respect to the active layer, and
θ1<θ2

where θ 1 denotes a tilt angle of a side of the active layer and the spacer layer of the mesa structure of the photo-sensing element and θ 2 denotes a tilt angle of a side of the reflector.

6 . The optical sensor according to claim 4 , wherein
the at least one surface-emitting laser element and the photo-sensing element are optically attached to each other at least via the spacer layer.

7 . The optical sensor according to claim 6 , wherein
the at least one surface-emitting laser element and the photo-sensing element have a portion that optically connects the surface-emitting laser element and the photo-sensing element, the portion having an optical thickness equivalent to an oscillation wavelength λ of the surface-emitting laser element.

8 . The optical sensor according to claim 4 , wherein
the multilayered structure further includes an insulator film disposed above the spacer layer, and the at least one surface-emitting laser element and the photo-sensing element are optically attached to each other at least via the insulator film.

9 . The optical sensor according to claim 8 , wherein
the insulator film has a refractive index smaller than a refractive index of the spacer layer.

10 . The optical sensor according to claim 8 , wherein
the insulator film has a surface roughness equal to or less than one-tenths of oscillation wavelength λ of the at least one surface-emitting laser element.

11 . The optical sensor according to claim 8 , wherein
the insulator film is composed of silicon oxide or silicon nitride.

12 . The optical sensor according to claim 1 , wherein
the at least one surface-emitting laser element comprises a plurality of surface-emitting laser elements to irradiate an identical point of the test object with a plurality of light rays that are not parallel to each other.

13 . The optical sensor according to claim 1 , wherein
the light irradiator further comprises an optical system disposed between the multilayered structure and the test object.

14 . The optical sensor according to claim 13 , wherein
the detection system includes at least one photodetector having a plurality of photoreceptors to detect a plurality of light rays that are emitted from the irradiation system to the test object and have propagated through the test object.

15 . The optical sensor according to claim 14 , wherein
the photodetector has a member disposed between the test object and the plurality of photoreceptors and the member has a transmissive portion thereon, and some of each of the plurality of light rays that have propagated through the test object passes through the transmissive portion.

16 . An optical examination device comprising:
an optical sensor including
an irradiation system including at least one light irradiator to irradiate a test object with light, and
a detection system to detect the light that is emitted from the irradiation system to the test object and has propagated through the test object; and
a controller to calculate optical properties of the test object based on a detection result of the optical sensor, wherein the light irradiator includes a multilayered structure having an active layer, the multilayered structure including at least one surface-emitting laser element and a photo-sensing element optically connected to the at least one surface-emitting laser element.

17 . A method of detecting optical properties, the method comprising:
performing optical simulation to obtain a detection light quantity distribution for an optical model that simulates a test object; and performing inverse problem estimation using a result of the optical simulation.

Assignees

• Ishii Toshihiro
• Takahashi Yoichiro
• Chubachi Sunao
• Fujiwara Masayuki
• Sasaki Toshihide
• Adachi Kazuhiko
• Ricoh Co Ltd

Inventors

• Ishii Toshihiro
• Takahashi Yoichiro
• Chubachi Sunao
• Fujiwara Masayuki
• Sasaki Toshihide
• Adachi Kazuhiko

Classifications

• A61B5/0042

  for the brain · CPC title

• A61B5/0073

  by tomography, i.e. reconstruction of 3D images from 2D projections (A61B5/0066 takes precedence) · CPC title

• A61B5/165

  Evaluating the state of mind, e.g. depression, anxiety · CPC title

• H01S5/0262 Primary

  Photo-diodes, e.g. transceiver devices, bidirectional devices (H01S5/0265 takes precedence) · CPC title

• H01L31/022408

  Electricity · mapped topic