Three-Phase Spectral Interferometry with 120° Optical Splitter Calibration
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Solution Overview
Problem
Existing optical recorders face limitations in achieving both high resolution and long record lengths, with current technologies struggling to maintain fidelity at 1 ps or finer resolution and record lengths exceeding 1 ns.
Innovation Solution
A three-phase spectral interferometry technique that utilizes a three-output optical splitter with 120-degree phase shifts to measure three interferograms simultaneously, allowing for the determination of amplitude and phase values of input optical signals, and includes calibration methods to mitigate polarization and spectral response variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spectral interferometry is used to extend record length, then temporal resolution improves, but fidelity deteriorates due to polarization mismatch and phase jitter
Solution Approach 1:
The patent implements feedback by measuring the reference pulse characteristics and using this information to compensate for polarization mismatch and phase jitter effects. The system measures the reference pulse through the optical splitter and processes this information to correct measurement artifacts, thereby maintaining high fidelity while achieving extended record length with high temporal resolution.
Solution Approach 2:
The patent changes the measurement approach by introducing a reference pulse with known characteristics and using an optical splitter to create multiple paths with controlled phase shifts. This parameter change enables simultaneous measurement of signal and reference pulses, allowing for compensation of polarization and phase effects while maintaining high temporal resolution and extended record length.
2Measurement precision
If conventional spectral interferometry is used, then temporal resolution achieves less than 1 ps, but record length is limited to less than 1 ns
Solution Approach 1:
The patent transitions from traditional time-domain measurement to spectral domain measurement using spectral interferometry. By measuring the spectral content and using Fourier transform relationships, the system achieves both fine temporal resolution (less than 1 ps) and extended record length (beyond 1 ns), effectively adding a spectral dimension to the measurement process.
Solution Approach 2:
The patent introduces a reference pulse as an intermediary element that enables the measurement of unknown signal characteristics. The reference pulse with known properties serves as a mediator to extract temporal information from the signal through interference patterns, allowing simultaneous achievement of high temporal resolution and long record length.
3Measurement precision
If existing spectral interferometry techniques are used, then measurement sensitivity improves, but accuracy deteriorates due to lack of calibration for polarization and phase effects
Solution Approach 1:
The patent implements feedback by measuring the reference pulse characteristics and using this information to compensate for polarization mismatch and phase jitter effects. The system measures the reference pulse through the optical splitter and processes this information to correct measurement artifacts, thereby maintaining high fidelity while achieving extended record length with high temporal resolution.
Solution Approach 2:
The patent performs preliminary calibration by measuring the reference pulse characteristics before using them to correct signal measurements. This preliminary action allows the system to characterize and compensate for polarization and phase effects in advance, improving accuracy while maintaining high sensitivity.
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 technique achieves significantly improved spectral resolution (10×-100×) and temporal record length, enhances accuracy and sensitivity in signal retrieval, and compensates for polarization-dependent phase effects, enabling the measurement of chirped signals beyond the record length.
Implementation Method 1
a three-output optical splitter including: a first input port configured to receive the input optical signal, a second input port configured to receive a reference optical signal... each configured to produce an optical output signal based on the input and the reference optical signals, wherein each of a first, a second and a third optical signal produced by a corresponding output port has a relative phase shift of 120 degrees with respect to any of the other output optical signals
Implementation Method 2
one or more optical detectors positioned to receive the first, the second and the third optical signals, and to measure spectra corresponding to three interferograms associated with the first, the second and the third optical signals
Data Source
AI summary
Methods, systems and devices are described that enable measurement and characterization of complex laser pulses by relying on three interferograms that are measured simultaneously. The described three-phase spectral interferometry (3PSI) can meet the growing demand for optical recorders with long record and 1 ps or finer resolution. An example three-phase interferometric system includes a three-output optical splitter with a first input port to receive the input optical signal, a second input port to receive a reference optical signal with one or more unknown spectral characteristics. The three output ports of the optical splitter produce interferograms that correspond to relative phase shifts of substantially 120 degrees. Detectors are positioned to receive and measure the interferograms, which allows determination of the amplitude and phase of the input optical signal with very high accuracy. The described techniques include may improvements in the alignment, calibration and signal retrieval procedures associated with the 3PSI system.