Agile Optical Coherence Tomography System with Tunable VCL Laser
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Solution Overview
Problem
Spectral Domain OCT systems face limitations in imaging speed, range, and sensitivity due to sensitivity roll-off with increasing depth, and Swept Source OCT systems are constrained by coherence length and sweep speed limitations, making them less adaptable for long-range, high-speed, and high-dynamic-range imaging.
Innovation Solution
An optical coherence tomography system utilizing a vertical cavity laser (VCL) source with a tunable wavelength range and adjustable imaging modes, enabling flexible operation across various imaging speeds, ranges, and resolutions, and incorporating a monitoring detector for feedback to optimize performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If Spectral Domain OCT is used to achieve fast imaging speeds, then imaging speed is improved, but sensitivity roll-off occurs with increasing imaging depth
Solution Approach 1:
The patent changes the fundamental operating parameters of the OCT system by transitioning from spectral domain detection to swept source detection. This involves changing the light source from a broadband source to a wavelength-tunable laser, and changing the detection method from spatial spectral analysis to temporal frequency sweeping. These parameter changes enable the system to achieve fast imaging speeds while maintaining sensitivity across extended imaging depths by eliminating the sensitivity roll-off inherent in spectral domain approaches.
Solution Approach 2:
The patent implements dynamic adaptability by making the imaging system capable of adjusting its operating parameters in real-time. The swept source OCT system can dynamically tune the laser wavelength across different ranges and adjust the sweep repetition rate to match varying imaging requirements. This dynamic capability allows the system to optimize performance for different imaging depths and speeds, resolving the contradiction between maintaining sensitivity and achieving fast imaging.
2Length of stationary object
If Swept Source OCT is used to extend imaging range, then imaging range is improved, but coherence length and sweep speed limitations reduce adaptability
Solution Approach 1:
The patent implements dynamic adaptability by making the imaging system capable of adjusting its operating parameters in real-time. The swept source OCT system can dynamically tune the laser wavelength across different ranges and adjust the sweep repetition rate to match varying imaging requirements. This dynamic capability allows the system to optimize performance for different imaging depths and speeds, resolving the contradiction between maintaining sensitivity and achieving fast imaging.
Solution Approach 2:
The patent creates a universal imaging system that can perform multiple imaging functions with a single platform. By implementing a swept source laser with broad tuning capability and a flexible detection system, the patent enables the same hardware to adapt to various imaging scenarios including extended depth imaging, high-speed imaging, and different resolution requirements. This multi-functionality resolves the contradiction by making the system adaptable to diverse applications rather than being constrained by fixed coherence length and sweep speed limitations.
3Device complexity
If fixed operating modes are used to simplify system design, then device complexity is reduced, but imaging flexibility is limited
Solution Approach 1:
The patent implements dynamic adaptability by making the imaging system capable of adjusting its operating parameters in real-time. The swept source OCT system can dynamically tune the laser wavelength across different ranges and adjust the sweep repetition rate to match varying imaging requirements. This dynamic capability allows the system to optimize performance for different imaging depths and speeds, resolving the contradiction between maintaining sensitivity and achieving fast imaging.
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 system achieves enhanced dynamic range imaging, multiscale measurement capabilities, and improved agility, allowing for extended imaging ranges and high fundamental imaging speeds, overcoming previous limitations in OCT technology.
Implementation Method 1
a wavelength tunable vertical cavity laser (VCL) source generating wavelength sweeps
Implementation Method 2
Optical Coherence Tomography uses the interference pattern obtained by combining light backscattered or backreflected from a sample with light from a reference arm
Data Source
AI summary
An agile optical imaging system for optical coherence tomography imaging using a tunable source comprising a wavelength tunable VCL laser is disclosed. The tunable source has long coherence length and is capable of high sweep repetition rate, as well as changing the sweep trajectory, sweep speed, sweep repetition rate, sweep linearity, and emission wavelength range on the fly to support multiple modes of OCT imaging. The imaging system also offers new enhanced dynamic range imaging capability for accommodating bright reflections. Multiscale imaging capability allows measurement over orders of magnitude dimensional scales. The imaging system and methods for generating the waveforms to drive the tunable laser in flexible and agile modes of operation are also described.