Prism Wavelength-Selective Reflection for Compact Optical Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical systems in electronic devices, such as cameras and sensors, face challenges in miniaturization due to the need to separate visible light and infrared, as existing prisms typically reflect both wavelengths, leading to increased component sizes and complexity in light receiving systems.
Innovation Solution
A prism with a reflective face that totally reflects visible light while allowing only a part of the infrared to be reflected, utilizing a refractive index greater than √2 to 1.5 and a coating layer to absorb unreflected infrared, enabling separation of visible and infrared light within the prism, thereby reducing the size of the light receiving system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing prisms are used to reflect both visible light and infrared, then the light separation function is achieved, but the component size and system complexity increase
Solution Approach 1:
The patent changes the refractive index parameter of the prism material to a specific range (greater than √2 and less than or equal to 1.5) to achieve wavelength-selective total internal reflection. This parameter change enables the prism to differentiate between visible light and infrared based on their different refractive indices, achieving light separation without additional components
Solution Approach 2:
The patent employs composite optical structures by combining the prism with specific coating layers (including infrared-absorbing coatings) to create a composite optical element. This composite approach allows the system to achieve both visible light reflection and infrared absorption/filtering in a single integrated component, reducing overall system complexity
2Reliability
If existing prisms reflect both visible light and infrared, then the light separation function is achieved, but the component size increases
Solution Approach 1:
By changing the refractive index parameter to a specific range, the patent enables more efficient total internal reflection for visible light while allowing infrared to pass through or be absorbed. This improves the effectiveness of the light separation function, reducing the need for additional separation components and thereby reducing overall component size
Solution Approach 2:
The patent extracts the infrared component from the mixed light beam by allowing it to pass through the prism differently than visible light. The infrared-absorbing coating layers selectively remove infrared energy, separating it from the visible light path. This extraction approach consolidates multiple functions into a single prism component, reducing the volume required for light separation
3Loss of energy
If the refractive index is increased to improve visible light reflection, then the reflection efficiency improves, but the infrared absorption capability may be affected
Solution Approach 1:
The patent optimizes the refractive index parameter to a specific range (greater than √2 and less than or equal to 1.5) that simultaneously provides high visible light reflection efficiency through total internal reflection and appropriate infrared transmission/absorption characteristics. This parameter optimization balances both optical functions within the prism
Solution Approach 2:
The patent uses composite optical structures by combining the prism with infrared-absorbing coating layers. The coating layers compensate for any infrared transmission through the prism, ensuring reliable infrared absorption while maintaining the high visible light reflection efficiency provided by the optimized refractive index of the prism material
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for the miniaturization of electronic devices by reducing the size of components needed for infrared removal, enhancing the reliability of the optical system and facilitating the separation of visible and infrared light, resulting in a more compact and efficient light receiving system.
Implementation Method 1
Visible light of incident light is totally reflected from the reflective face
Implementation Method 2
a coating layer arranged outside the prism and in contact with the reflective face
Data Source
AI summary
A prism includes an incident face on which incident light including visible light and infrared is incident, a reflective face from which at least a part of incident light is reflected, and an exit face from which reflected light is emitted. Visible light of incident light is totally reflected from the reflective face, and only a part of infrared of incident light is totally reflected from the reflective face.