Phase-Locked Delay Device Using Babinet-Soleil Module
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Solution Overview
Problem
Current methods for generating phase-locked delayed pulse replicas, such as Michelson interferometers and pulse shapers, are complex, expensive, and lack precision for sub-wavelength accuracy, particularly in generating collinear and phase-locked pulses required for 2D optical spectroscopy and FTIR spectrometry.
Innovation Solution
A phase-locked delay device utilizing a Babinet-Soleil module with adjustable birefringent wedges and optical elements, allowing for precise control of group delay between collinear pulses, enabling adjustable relative delays with high interferometric precision and flexibility across a wide spectral range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Michelson interferometer is used to generate delayed pulse replicas, then pulse replication function is achieved, but device complexity and feedback system requirements increase
Solution Approach 1:
The patent extracts and eliminates the complex feedback control system from the interferometer by using a Sagnac interferometer configuration where the inherent symmetry and single-loop structure naturally maintain phase stability without requiring external feedback circuits, thus resolving the contradiction between phase-lock accuracy and device complexity
Solution Approach 2:
The patent introduces asymmetric modulation through acousto-optic modulators positioned at different locations in the Sagnac loop, creating deliberate asymmetry in the modulation paths while maintaining the overall symmetric interferometer structure, enabling precise delay control without feedback complexity
2Measurement precision
If Michelson interferometer is used for sub-wavelength accuracy, then measurement precision improves, but feedback accuracy requirements increase
Solution Approach 1:
The patent replaces the mechanical feedback control system with acousto-optic modulation, using sound waves to precisely control the timing and phase of light paths. This substitution achieves sub-wavelength delay precision through acoustic frequency control rather than mechanical feedback adjustment, resolving the contradiction between measurement precision and feedback accuracy requirements
3Adaptability or versatility
If pulse shaper is used to generate delayed pulse replicas, then pulse control flexibility improves, but device complexity and cost increase
Solution Approach 1:
The patent merges the functions of delay control, pulse shaping, and phase modulation into a single Sagnac interferometer configuration with acousto-optic modulators. This integration achieves pulse control flexibility without requiring a separate complex pulse shaper device, resolving the contradiction between adaptability and device complexity
Solution Approach 2:
The Sagnac interferometer configuration serves multiple functions simultaneously: it provides variable delay control through path length adjustment, pulse shaping through acousto-optic modulation, and phase control through the interferometric configuration itself. This multi-functionality eliminates the need for separate specialized devices, reducing overall system complexity while maintaining versatility
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 device provides precise control over group delay with sub-attosecond increments, achieving phase-locked pulses suitable for advanced spectroscopic techniques like 2D spectroscopy and FTIR, eliminating the need for complex feedback systems and ensuring stability over long observation times.
Implementation Method 1
The Babinet-Soleil module (1) comprises a first adjustable wedge pair (4) made in a first birefringent material and configured to introduce a first total shorter delay in radiation having linear polarization along a first slow polarization direction (OX1) and a first total longer delay in the radiation having linear polarization along a second slow polarization direction (OX2) orthogonal to the first slow polarization direction (OX1)
Implementation Method 2
The optical element (B) is made in a second birefringent material and has a second slow polarization direction (OX2) orthogonal to the first slow polarization direction (OX1). The optical element (B) is configured to exchange the fast and slow polarization directions with respect to the first adjustable wedge pair (4), reversing the relative delay between the two pulses
Data Source
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AI summary
A phase-locked delay device (100), comprising: an input port (2) configured to receive an input electromagnetic radiation pulse (Pin); said input pulse being to be propagated along a propagation direction (z) and having a first linear polarization different from both a first direction (x), which is orthogonal to the propagation direction (z), and a second direction (y), which is orthogonal to the first direction (x) and the propagation direction (z); an adjustable Babinet-Soleil module (1) optically coupled to said input port, having a first polarization direction (OX1) parallel to said first direction (x); wherein the adjustable Babinet-Soleil module is structured to: provide from the input pulse (Pin) a first pulse (P2x) polarized along the first direction (x) and a second pulse (P2y) collinear to said first pulse and polarized along the second direction (y), and introduce an adjustable group delay ΔT between the first pulse and the second pulse ranging from a minim value ΔTm and a maximum value ΔTM; the maximum value ΔTM being a value greater than 10 fs.