Linear-Fan PIC Imager Configuration for Spatial Frequency Sampling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current photonic integrated circuit (PIC) imagers in segmented planar imaging detectors for electro-optical reconnaissance have limitations in achieving efficient, compact, and cost-effective configurations that can sample a broad distribution of spatial frequencies, leading to suboptimal image resolution due to the linear distribution of baseline lengths and orientations.

Innovation Solution

A linear-fan configuration of PIC imagers is developed, where multiple PIC units with lenslet arrays are randomly arranged on a substrate, embedding waveguides to optically couple pairs of lenslets, allowing for arbitrary orientation and spacing, thereby enhancing angular diversity and achieving a denser sampling of spatial frequencies in the U-V plane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If PIC imager units are arranged in a linear configuration, then the device structure is simple and easy to manufacture, but the sampling of spatial frequencies is insufficient leading to suboptimal image resolution

Engineering Contradiction:

Improvespatial frequency samplingVSAvoidconfiguration complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The imaging system is divided into multiple independent PIC imager units, each capable of sampling spatial frequencies. By segmenting the system into discrete units that can be independently positioned, the patent achieves denser sampling coverage in the U-V plane without requiring a monolithic complex structure

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from symmetric linear arrangements to asymmetric arbitrary configurations of PIC imager units. This asymmetric positioning allows units to be placed at optimized locations for maximum spatial frequency sampling efficiency, improving measurement precision while the modular nature keeps manufacturing manageable

Inventive Principle:

Principle #4Asymmetry

2Measurement precision

If more PIC imager units are added to enhance spatial frequency sampling, then image resolution is improved, but the overall size and mass of the system increases

Engineering Contradiction:

Improveimage resolutionVSAvoidsystem mass

Core Design Contradiction:

Measurement precisionVSWeight of stationary object

Solution Approach 1:

Multiple PIC imager units are merged into a single integrated system on one substrate. The waveguide arrays and optical connectors combine the functionality of multiple units, allowing dense packing that reduces overall system mass compared to distributed arrangements

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a nested structure where PIC imager units are integrated within a compact substrate framework. The waveguides and optical components are nested within the substrate, creating a space-efficient configuration that minimizes system footprint and mass while maintaining multiple imaging units

Inventive Principle:

Principle #7Nested doll (Nesting)

3Adaptability or versatility

If PIC imager units are arranged in arbitrary configurations, then angular diversity is enhanced for better interferometry performance, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improveangular diversityVSAvoidmanufacturing ease

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent creates universal PIC imager units that can function in multiple positions and orientations within the arbitrary configuration. Each unit is designed with standardized interfaces (optical connectors, waveguide couplings) that allow them to be universally positioned anywhere on the substrate, enabling arbitrary arrangements without increasing individual unit complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the positional parameters of PIC imager units from fixed linear arrangements to variable arbitrary coordinates on the substrate. This parameter optimization allows tailoring of angular diversity for specific interferometry applications while the underlying modular architecture maintains manufacturing simplicity through standardized unit designs

Inventive Principle:

Principle #35Parameter changes

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 configuration results in a compact, high-resolution imager with improved spatial frequency sampling, optimizing angular distribution and area coverage, which is crucial for interferometry applications, especially in airborne systems, by allowing for a tradeoff between additional units and overall size for enhanced resolution.

Implementation Method 1

Pairs of lenslets of the linear lenslet array are optically coupled to respective waveguides embedded in the PIC

Methodology Applied

Scientific EffectOptical coupling: Waveguide (optics)

Implementation Method 2

a number of lenslets configured as a linear lenslet array and optically coupled to an edge of the PIC

Methodology Applied

Scientific EffectLens focusing: Lens

Data Source

PatentUS10914900B1Linear-fan configuration of photonic integrated circuit imagers

Publication Date: 2021.02.09 LOCKHEED MARTIN CORP

AI summary

A photonic integrated circuit (PIC) imager includes a substrate, and a number of PIC imager units disposed in an arbitrary configuration on the substrate. Each PIC imager unit includes a PIC coupled to an optical connector, and a number of lenslets configured as a linear lenslet array and optically coupled to an edge of the PIC. Pairs of lenslets of the linear lenslet array are optically coupled to respective waveguides embedded in the PIC.