Tunable Surface Emission Laser for Deep OCT Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical coherent tomography systems using tunable light sources face limitations in measurement depth, size, and mass production due to the fiber-ring type laser's wide spectral width and complexity in high-speed wavelength scanning, while the end-face wavelength laser struggles with phase control for continuous scanning.
Innovation Solution
A tunable surface emission laser with a DBR layer structure and a driving mechanism that changes the cavity length using electrostatic force or bimorph effects, enabling continuous wavelength scanning in single mode, combined with a wavelength monitor and signal processing for high-resolution tomography imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If fiber-ring type laser is used for wavelength scanning, then high-speed scanning is achieved, but measurement depth is limited due to wide spectral width
Solution Approach 1:
The patent changes the fundamental parameter of spectral width by switching from fiber-ring type laser to surface emission laser. This parameter change enables simultaneous achievement of high scanning speed and narrow spectral width, resolving the contradiction between speed and measurement depth
2Speed
If fiber-ring type laser is used, then wavelength scanning capability is achieved, but device size cannot be reduced
Solution Approach 1:
The patent replaces the mechanical fiber-ring laser structure with a semiconductor-based surface emission laser. This substitution eliminates the need for complex fiber optics and mechanical components, achieving miniaturization while maintaining wavelength scanning capability
3Measurement precision
If end-face wavelength laser is used for single-mode tuning, then measurement depth is improved, but phase control for continuous scanning becomes complicated
Solution Approach 1:
The patent extracts the phase control complexity from the system by using surface emission laser's natural single-mode oscillation characteristics. This eliminates the need for complex phase control mechanisms while maintaining continuous wavelength scanning capability
4Speed
If fiber-ring type laser is used, then wavelength scanning is achieved, but mass production becomes difficult
Solution Approach 1:
The patent replaces the difficult-to-manufacture fiber-ring laser with a semiconductor surface emission laser that can be produced using standard semiconductor fabrication processes. This substitution enables mass production while maintaining wavelength scanning functionality
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 allows for high-speed wavelength scanning, improved detection sensitivity, and increased internal detectable depth, enabling the creation of high-sensitivity motion images with enhanced resolution and practicality for endoscopic applications.
Implementation Method 1
a driving mechanism that changes the cavity length using electrostatic force or bimorph effects
Implementation Method 2
a driving mechanism that changes the cavity length using electrostatic force or bimorph effects
Implementation Method 3
an interferometer for dividing the light from the tunable light source into a reference light and an emission light, and for generating interference light of reflecting light from an object and the reference light
Data Source
AI summary
A surface emission laser light source is used as a tunable laser light source. Since the surface emission laser light source can realize a broad frequency scanning range at a high speed and in the single mode, a coherent length is longer than that of a multi mode light source. For this reason, when a tomography image is calculated by executing the Fourier transform for an output obtained from an interference optical device, measuring depth can be deepened.