Optical Phased Array Receiver for Lens-Free Imaging
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Solution Overview
Problem
Conventional optical imaging systems face limitations in sensitivity and mechanical complexity, particularly in lens-free applications, where they struggle to efficiently detect and differentiate signal amplitudes and directions without mechanical movements.
Innovation Solution
An optical phased array receiver is developed, comprising multiple optical receiver elements, phase shifters, and optical-to-electrical signal converters, which electronically adjust phases to align signals for enhanced sensitivity and directional detection, allowing for lens-free imaging with improved sensitivity and a large field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional optical imaging systems are used without mechanical movements, then device simplicity is improved, but sensitivity and signal detection capability deteriorate
Solution Approach 1:
The patent replaces mechanical scanning systems with an optical phased array that uses electronic phase control to achieve directional signal detection. Multiple optical receiver elements (gratings) are arranged in a specific geometry, and their relative phases are controlled electronically through path length adjustments, eliminating the need for mechanical movements while maintaining or improving sensitivity through coherent signal combining.
Solution Approach 2:
The patent combines multiple optical receiver elements (gratings) into a single phased array system. By merging the signals from multiple elements and controlling their relative phases, the system achieves enhanced sensitivity through constructive interference of signals from desired directions while suppressing signals from other directions, thereby improving measurement precision without mechanical complexity.
2Measurement precision
If multiple sensors are arranged to receive optical signals from specific directions, then directional detection capability is improved, but collection area per sensor deteriorates
Solution Approach 1:
The patent segments the optical collection function across multiple grating elements arranged in a phased array. Each grating element can be relatively small in area, but by segmenting the overall array into multiple such elements with controlled phase relationships, the system achieves both directional detection capability and substantial total collection area through the combined effect of all elements.
Solution Approach 2:
The patent transitions from a single large sensor to multiple smaller sensors arranged in a multi-dimensional phased array configuration. By adding spatial arrangement and phase control dimensions, the system achieves directional detection capability without requiring each individual sensor to have large area, as the collective array provides both directionality and total collection area.
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 optical phased array receiver achieves enhanced sensitivity and numerical aperture, enabling fast, mechanical movement-free imaging with high accuracy and sensitivity, suitable for small form factor devices like smartphones and tablets, while maintaining a large collection area.
Implementation Method 1
a multitude of optical receiver elements receiving optical signals from the object... and at least one optical-to-electrical signal converter adapted to convert the multitude of phase-shifted optical signals to an electrical signal
Implementation Method 2
a multitude of phase shifters each associated with and receiving an optical signal from a different one of the optical receiver elements... causing phase-shifted optical signals generated by the phase shifters to be substantially in phase
Data Source
AI summary
An optical phased array (OPA) receiver selectively detects, measures and differentiates between the amplitudes and directions of signals received from different directions. Because the OPA changes the direction that it looks toward electronically and without the use of any mechanical movements, the OPA is fast, has an enhanced sensitivity, and can be used in a wide variety applications, such as lens-free imaging systems. The OPA is adapted to dynamically control the array of optical elements and focus on the area of interest. The OPA achieves a higher numerical aperture compared to imaging systems that use conventional lens, thereby effectively maintaining a relatively large field of view and collection area concurrently. The OPA may be readily scaled by increasing its array size. Furthermore, because the OPA is relatively flat, it is ideally suited for small form factor applications such as cell phones and tablets.