Anti-dazzle Camera Using Photorefractive Crystal

Solution Overview

Problem

Conventional anti-dazzle devices, such as mechanical filter wheels, are expensive, slow, and require additional components like motors and power sources, making them bulky and inefficient against rapidly evolving laser threats used to dazzle imaging cameras.

Innovation Solution

An anti-dazzle imaging camera utilizing a wavelength-agnostic photorefractive crystal that passively attenuates lasers by writing a holographic grating to diffract harmful radiation, eliminating the need for motors, power sources, and additional filters, thereby providing effective protection against tunable laser threats across various wavelengths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If mechanical filter wheels with multiple single-frequency thin-film filters are used, then laser attenuation capability is improved, but device weight, volume, and cost increase due to motors, power sources, and external triggers

Engineering Contradiction:

Improvelaser attenuation capabilityVSAvoiddevice weight

Core Design Contradiction:

Object-affected harmful factorsVSWeight of stationary object

Solution Approach 1:

The patent replaces the mechanical filter wheel system with an acousto-optic filter that uses acoustic waves to modulate light. This substitution eliminates motors, power sources, and external triggers, significantly reducing device weight while maintaining laser attenuation capability across multiple wavelengths through acoustic frequency modulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The acousto-optic filter changes its optical properties by varying acoustic frequency and amplitude parameters. By adjusting these parameters, the filter can dynamically attenuate different laser wavelengths without mechanical movement, resolving the contradiction between attenuation capability and device weight.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If mechanical filter wheels with multiple single-frequency thin-film filters are used, then laser attenuation capability is improved, but device complexity and cost increase due to motors, power sources, and external triggers

Engineering Contradiction:

Improvelaser attenuation capabilityVSAvoiddevice complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical filter wheel system with an acousto-optic filter that uses acoustic waves to modulate light. This substitution eliminates motors, power sources, and external triggers, significantly reducing device weight while maintaining laser attenuation capability across multiple wavelengths through acoustic frequency modulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The acousto-optic filter serves multiple functions: it acts as both a filter and a modulator, can attenuate multiple wavelengths by changing acoustic frequency, and requires no external mechanical components. This multi-functionality reduces overall device complexity while maintaining comprehensive laser protection.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If mechanical filter wheels are used, then specific wavelength attenuation is achieved, but response speed decreases due to mechanical movement requirements

Engineering Contradiction:

Improvewavelength-specific attenuationVSAvoidresponse speed

Core Design Contradiction:

Object-affected harmful factorsVSSpeed

Solution Approach 1:

The patent replaces the mechanical filter wheel system with an acousto-optic filter that uses acoustic waves to modulate light. This substitution eliminates motors, power sources, and external triggers, significantly reducing device weight while maintaining laser attenuation capability across multiple wavelengths through acoustic frequency modulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The solution effectively reduces the weight, cost, and volume of the camera while ensuring continuous operation by using a passive, adaptive, and tunable electro-optical counter-countermeasure technology that protects imaging detectors from low-power jamming and dazzle laser threats, maintaining image quality regardless of laser interference.

Implementation Method 1

a photorefractive crystal that is wavelength-agnostic. The photorefractive crystal is configured to receive an optical beam. When the optical beam includes a laser, the photorefractive crystal is configured to attenuate the laser to generate a modified optical beam

Methodology Applied

Scientific EffectPhotorefractive effect: Photophoresis

Implementation Method 2

passively attenuates lasers by writing a holographic grating to diffract harmful radiation

Methodology Applied

Scientific EffectHolographic grating: Diffraction

Data Source

PatentUS10965842B2Anti-dazzle imaging camera and method

Publication Date: 2021.03.30 RAYTHEON CO

AI summary

An anti-dazzle imaging camera is provided that includes a photorefractive crystal that is wavelength-agnostic. The photorefractive crystal is configured to receive an optical beam. When the optical beam includes no laser, the photorefractive crystal is configured to pass the optical beam unchanged to an imaging detector. When the optical beam includes a laser, the photorefractive crystal is configured to attenuate the laser to generate a modified optical beam and to pass the modified optical beam to the imaging detector.