CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application Nos. 10-2019-0082161 filed on Jul. 8, 2019 and 10-2019-0082162 filed on Jul. 8, 2019 and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which are incorporated by reference in their entirety.

BACKGROUND

The present disclosure relates to an apparatus and a method for infrared imaging, and more particularly, to an apparatus and a method for infrared imaging, which receive infrared light emitted from a target and output the received infrared light as an image.

A key component of thermal imaging equipment that senses the difference between the intrinsic radiant energies released from a target at night without light is an infrared imaging system, such as an infrared camera.

A conventional infrared camera is mainly fabricated on the basis of a quantum well infrared photodetector (QWIP) based on indium gallium arsenide (InGaAs), which is a compound semiconductor. The QWIP detects an electrical signal that is obtained when InGaAs absorbs the quantums in the near-infrared band and excites the electrons to a high energy level.

However, the QWIP is fabricated with expensive equipment and through a complex process, and the low production and the high price are becoming a barrier to the development of the related industries. Further, the transaction of InGaAs is restricted by the international traffic in arms regulations (ITAR). Thus, research on an infrared detector that can replace such a QWIP is being conducted.

SUMMARY

The present disclosure provides an apparatus and a method for infrared imaging, which may output an image by using, as measurement light, infrared light emitted from a target.

In accordance with an exemplary embodiment, an infrared imaging apparatus for receiving infrared light emitted from a target and outputting the received infrared light as an image detects measurement light having a wavelength band different from that of the infrared light and the light quantity thereof changing depending on the infrared light and outputs the detected measurement light as an image.

The infrared imaging apparatus may include: a reaction unit including a reactive layer with physical properties changing in response to the received infrared light; a light source unit disposed to irradiate the reaction unit with the measurement light; and an imaging unit disposed to detect the measurement light having passed through the reaction unit.

The measurement light may include visible light, and the imaging unit may include an image sensor configured to convert the visible light into electric charges and output the electric charges as an image.

The reaction unit may further include: a dielectric; and a metal layer provided on the dielectric, wherein the reactive layer is provided on the metal layer.

The light source unit may be disposed to irradiate a surface of the metal layer with the measurement light via the dielectric at a preset incident angle, and the imaging unit may be disposed to detect the measurement light reflected from the surface of the metal layer.

The light source unit may be disposed such that the measurement light is emitted at an incident angle at which the measurement light resonates with surface plasmons of the metal layer while the infrared light is not input thereto.

The reactive layer may include: an absorption layer formed of nanoparticles each including a quantum dot and provided on the metal layer; and an electric charge supply layer having a liquid state and provided on the absorption layer.

The quantum dot may include PbS and/or PbSe, and the electric charge supply layer may include triethanolamine-hydrochloride (TEA-HCl).

The reactive layer may further include an electric charge accumulation layer formed of metal nanoparticles and provided between the metal layer and the absorption layer.

The reactive layer may include a liquid crystal layer formed by dispersing, into liquid crystal, graphene nanoparticles or reduced graphene oxide nanoparticles.

The imaging unit may be disposed to detect the measurement light having passed through the reaction unit.

The light source unit may include a first polarizing plate configured to polarize the measurement light output from a light source, and the imaging unit may include a second polarizing plate configured to polarize the measurement light having passed through the reaction unit.

The first polarizing plate and the second polarizing plate may have optical axes in the same direction as each other or in directions orthogonal to each other.

The light source unit may be disposed to emit the measurement light in a direction crossing an input direction of the infrared light, and the reaction unit may further include a path adjustment part disposed at a position at which the input direction of the infrared light crosses an irradiation direction of the measurement light to input the infrared light and the measurement light to the reactive layer in the same direction.

The path adjustment part may include a dichroic mirror configured to transmit the infrared light and reflect the measurement light.

The reactive layer may include a liquid crystal layer formed by dispersing, into liquid crystal, graphene nanoparticles or reduced graphene oxide nanoparticles.

In accordance with another exemplary embodiment, an infrared imaging method includes: inputting infrared light, emitted from a target, to a reaction unit; irradiating the reaction unit with measurement light; detecting the measurement light with the light quantity thereof changing depending on a change in the physical properties of at least a portion of the reaction unit due to the infrared light; and outputting the distribution of the light quantity of the detected measurement light.

The irradiating of the measurement light may include irradiating, with the measurement light, an area in which regions, to which the infrared light is input, are all superimposed.

The detecting of the measurement light may include: changing the reflectance of the measurement light depending on the change in the physical properties of the at least a portion of the reaction unit; and detecting the measurement light with the changed reflectance.

The detecting of the measurement light may include: changing the transmittance of the measurement light depending on the change in the physical properties of the at least a portion of the reaction unit; and detecting the measurement light with the changed transmittance.

