Refractive Optical Delay System for Compact Interferometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional optical delay systems in time-domain interferometry are large, slow, and introduce unwanted variance due to the movement of mirrors, complicating alignment and precision in laboratory settings.
Innovation Solution
A compact optical delay system using a refractive medium that modulates the optical path length by rotating a transparent medium with a high index of refraction and low dispersion coefficient, creating discrete or continuous delays based on the rotation angle, allowing for precise control of light interference patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional optical delay line using moving mirrors is used, then the optical path length can be modulated, but the system becomes large, slow, and introduces unwanted variance
Solution Approach 1:
The patent replaces the mechanical mirror system with an acousto-optic modulator (AOM) that uses acoustic waves to diffract and delay light. This substitution eliminates mechanical moving parts, reducing system complexity and unwanted variance while maintaining precise optical path length modulation capability
Solution Approach 2:
The patent changes the control parameter from mechanical mirror position to acoustic frequency applied to the AOM. By varying the acoustic frequency, the optical delay can be precisely controlled without mechanical movement, improving precision while reducing device complexity
2Ease of operation
If mirrors are moved to create distance variations, then optical interference patterns can be generated, but alignment and precision of movement become complicated
Solution Approach 1:
The patent replaces mechanical mirror movement with an acousto-optic modulation system. The AOM uses sound waves to create a moving diffraction grating that delays light without any mechanical displacement, dramatically simplifying alignment while maintaining precise delay control through electrical frequency modulation
Solution Approach 2:
The patent introduces acoustic waves as an intermediary to achieve optical delay. The acoustic field in the AOM acts as a mediator that converts electrical control signals into optical path length variations, eliminating the need for precise mechanical mirror positioning and alignment
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 solution enables the creation of compact interferometry equipment that can be used outside laboratory environments with reduced variance and improved precision, facilitating the detection of small features in samples through coherent optical signals.
Implementation Method 1
A compact optical delay system using a refractive medium that modulates the optical path length by rotating a transparent medium with a high index of refraction
Implementation Method 2
the time of flight of the transmitted light is delayed by discrete values, determined by the profile of the rotating medium, due to the difference in refractive index between the transparent medium and air
Implementation Method 3
two coherent optical signals are superimposed spatially and temporally, and modulated by a sample somewhere in the optical path
Data Source
AI summary
The disclosed discrete or continuous optical delay is a medium with high transmission, a high index of refraction and a low dispersion coefficient at the wavelength of light of interest. One side of the medium, orthogonal to the incident light, is fabricated to delay the light at discrete values in a periodic pattern that repeats as the optical delay rotates. The disclosed discrete or continuous optical delay enables the creation of compact interferometry equipment to be used outside a laboratory environment.