Quantum Absorption Spectroscopy System Wavelength Scanning
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Solution Overview
Problem
In quantum absorption spectroscopy, there is a demand to broaden the wavelength range for measuring absorption spectroscopy characteristics of a sample and to shorten measurement time, as existing methods can result in excessively long measurement times when targeting a wide wavelength range.
Innovation Solution
A quantum absorption spectroscopy system that includes a quantum optical system causing quantum interference between physical processes generating a quantum entangled photon pair. This system uses a nonlinear optical element, a wavelength scanner, and an optical path sweeper to scan wavelengths and sweep optical path differences, allowing for fast measurement of absorption spectroscopy characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the wavelength range is broadened to measure absorption spectroscopy characteristics over a wide range, then the measurement capability is improved, but the measurement time becomes excessively long
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between the control parameter (e.g., pump light wavelength) and the generated quantum entangled photon pair wavelengths. This allows the system to quickly switch between different wavelength ranges by simply changing the control parameter without performing time-consuming wavelength calibration or scanning procedures for each measurement, thus enabling wide wavelength range coverage while maintaining short measurement times
Solution Approach 2:
The patent utilizes parameter changes by varying the control parameter (such as pump light wavelength or nonlinear optical element temperature) to generate quantum entangled photon pairs at different wavelengths. This enables the system to cover a wide wavelength range by simply adjusting the control parameter, avoiding the need for physical reconfiguration or time-consuming scanning procedures, thereby resolving the contradiction between wide wavelength coverage and short measurement time
2Adaptability or versatility
If conventional absorption spectroscopy methods are used to cover a wide wavelength range, then the wavelength coverage is improved, but the measurement speed decreases
Solution Approach 1:
The patent replaces mechanical scanning systems (such as moving mirrors or gratists that physically scan through wavelengths) with a quantum optical system where the wavelength is controlled by adjusting parameters of the photon generation process. This substitution of mechanical scanning with quantum parameter control enables rapid wavelength switching without mechanical movement, thereby achieving both wide wavelength coverage and high measurement speed
Solution Approach 2:
The patent employs periodic action by using pulsed pump light to generate quantum entangled photon pairs at different wavelengths in a systematic sequence. By periodically varying the pump light parameters and synchronizing the detection with the pulse timing, the system efficiently collects spectral information across a wide wavelength range at high speed, improving both wavelength coverage and measurement speed
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 enables measurement of absorption spectroscopy characteristics over a wide wavelength range at high speed, addressing the challenge of long measurement times in existing technologies.
Implementation Method 1
The nonlinear optical element generates the quantum entangled photon pair by irradiation with pump light
Implementation Method 2
a quantum optical system that causes quantum interference between a plurality of physical processes in which a quantum entangled photon pair of a signal photon and an idler photon is generated
Implementation Method 3
The wavelength scanner scans a wavelength of the quantum entangled photon pair by changing a control parameter
Implementation Method 4
The optical path sweeper sweeps an optical path difference between the signal photon and the idler photon
Implementation Method 5
The photodetector outputs a signal depending on a detected number of the signal photons
Data Source
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AI summary
A rotation stage (105) scans a wavelength of a quantum entangled photon pair by changing a crystal rotation angle θ. A moving mirror (110) and a driver (111) sweep an optical path difference between a signal photon and an idler photon. A photodetector (81) outputs a signal according to the signal count in a state where a target sample is disposed in an optical path of the idler photon. A processor (91) acquires, each time the wavelength is sequentially changed by changing crystal rotation angle (θ), a quantum interference signal under a condition that a sweep range of the optical path difference is limited compared with when sweeping the optical path difference to acquire an entire envelope of the quantum interference signal, or under a condition that the optical path difference is fixed, calculates amplitude of an interference fringe that appears in the acquired quantum interference signal, and calculates, based on the calculated amplitude of the interference fringe, an absorption spectroscopy characteristic at a wavelength of the idler photon corresponding to crystal rotation angle (θ).