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US 11,454,819 B2Granted
Polarization conversion element and optical isolation device
AssigneeLG Chem, Ltd.
InventorSang Choll Han
Life of this patent
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Abstract
The present application relates to a polarization conversion element and an optical isolation device. The present application provides a polarization conversion element capable of converting unpolarized incident light into one polarized light and an optical isolation device with an excellent optical isolation ratio comprising the polarization conversion element. Such an optical isolation device can be applied to various applications such as the field of optical communication or laser optics, the field of security or privacy protection, brightness enhancement of displays, or a use for hiding and covering.
Claims14
An optical isolation device comprising at least one optical isolation element,
- wherein the optical isolation element comprises a polarizer and a polarization conversion element for converting unpolarized incident light into one polarized light exiting the polarization conversion element,
- wherein the polarizer is an absorbing linear polarizer,
- wherein the polarization conversion element comprises a retroreflector, a retarder and a reflective polariscope,
- wherein the unpolarized incident light comprises a vertical mode pair of a first polarized light and a second polarized light,
- wherein the first polarized light is transmitted through the reflective polariscope and the second polarized light is reflected by the reflective polariscope,
- wherein the second polarized light reflected by the reflective polariscope is incident on the retroreflector, and
- wherein the retroreflector and the reflective polariscope are disposed such that the unpolarized incident light comprising the vertical mode pair is incident on the reflective polariscope and the second polarized light is reflected by the reflective polariscope to the retroreflector,
- wherein the polarization conversion element has a transmittance of 60% or more, the transmittance being a ratio of the one polarized light exiting the polarization conversion element relative to the unpolarized incident light, and
- wherein the retarder is positioned between the retroreflector and the reflective polariscope such that the second polarized light reflected by the reflective polariscope is incident on the retroreflector after passing through the retarder.
6 more elements
An optical isolation device comprising at least one optical isolation element,
- wherein the optical isolation element comprises a polarizer and a polarization conversion element for converting unpolarized incident light into one polarized light exiting the polarization conversion element,
- wherein the polarizer is an absorbing linear polarizer,
- wherein the polarization conversion element and the polarizer are sequentially disposed,
- wherein the polarization conversion element comprises a retroreflector and a reflective polariscope,
- wherein the unpolarized incident light comprises a vertical mode pair of a first polarized light and a second polarized light,
- wherein the first polarized light is transmitted through the reflective polariscope and the second polarized light is reflected by the reflective polariscope,
- wherein the second polarized light reflected by the reflective polariscope is incident on the retroreflector,
- wherein the polarization conversion element further comprises a retarder at a position where the first polarized light transmitted through the reflective polariscope can be incident,
- wherein the reflective polariscope is a cholesteric liquid crystal film, and
- wherein the polarization conversion element has a transmittance of 60% or more, the transmittance being a ratio of the one polarized light exiting the polarization conversion element relative to the unpolarized incident light.
7 more elements
An optical isolation device, comprising at least two optical isolation elements,
- wherein each of the optical isolation elements comprises a polarizer and a polarization conversion element for converting unpolarized incident light into one polarized light exiting the polarization conversion element, the polarization conversion element and the polarizer being sequentially disposed,
- wherein the polarization conversion element comprises a retroreflector and a reflective polariscope,
- wherein the unpolarized incident light comprises a vertical mode pair of a first polarized light and a second polarized light,
- wherein the first polarized light is transmitted through the reflective polariscope and the second polarized light is reflected by the reflective polariscope,
- wherein the second polarized light reflected by the reflective polariscope is incident on the retroreflector and
- wherein the optical isolation elements are disposed so that light transmitted through a first of the at least two optical isolation elements can enter a side of the polarization conversion element of a second of the at least two optical isolation elements.
3 more elements
Dependencies are inferred from the claim text.