Integrated Laser Source for Cold-Atom Inertial Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cold-atom inertial sensors require complex and bulky laser systems for stabilization, making them incompatible with compact on-board applications, or are extremely costly due to the need for precise alignment and bonding of miniature optical components.
Innovation Solution
A simplified laser-source assembly using a master laser with a control loop and a slave laser with an optical phase-locked loop, where the slave frequency is offset to achieve stabilization, allowing for integrated optic realization and reduced bulk and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex laser systems with multiple optical components are used for frequency stabilization, then measurement precision is improved, but device complexity and bulk increase
Solution Approach 1:
The patent combines multiple laser systems into a single integrated laser source that generates all required frequencies (cooling, repumping, detection) through frequency multiplication and modulation of a fundamental frequency. This merging eliminates the need for separate laser systems and reduces overall device complexity while maintaining frequency stabilization precision through a unified control architecture.
Solution Approach 2:
The laser source is designed as a universal multi-functional device that can generate multiple frequencies (780nm cooling, 773nm repumping, 390nm detection) from a single fundamental frequency through non-linear optical processes. This multi-functionality reduces the number of components needed while maintaining the precision required for each specific function.
2Measurement precision
If precise alignment and bonding of miniature optical components is performed, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces complex mechanical alignment and bonding of multiple optical components with an integrated photonic circuit implementation. The frequency stabilization is achieved through electronic control and feedback mechanisms within a single integrated device, eliminating the need for precise mechanical assembly while maintaining measurement precision.
3Adaptability or versatility
If multiple separate laser systems are used for different atomic transitions, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent achieves multiple frequencies and adaptability by changing parameters of a single laser system through frequency multiplication (x2, x4), modulation, and offset locking techniques. This allows the same physical laser to provide different frequencies (780nm, 773nm, 390nm) required for different atomic transitions, maintaining versatility while reducing component count.
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 solution enables a compact and cost-effective laser system for cold-atom inertial sensors, compatible with integrated optic technology, improving the feasibility of on-board applications by stabilizing laser frequencies with high precision using a single atomic cell and optical phase-locked loops.
Implementation Method 1
a second control loop in the form of an optical phase-locked loop that is configured to stabilise the slave frequency with respect to the master frequency
Implementation Method 2
The second control loop is made up of an optical phase-locked loop that is configured to achieve the stabilization on the basis of an error signal that is dependent on a phase difference between, on the one hand, a beat between the master frequency and the slave frequency
Data Source
AI summary
A laser-source assembly that is configured to illuminate a vacuum chamber containing atoms in the gaseous state so as to implement a cold-atom inertial sensor, the atoms having at least two fundamental levels that are separated by a fundamental frequency difference comprised between 1 and a few gigahertz, the assembly comprises: a master laser that emits a beam having a master frequency; a first control loop that is configured to stabilize the master frequency of the master laser on a frequency corresponding to half a set frequency of an atomic transition between a fundamental level and an excited level of the atoms; a slave laser that has a slave frequency; and a second control loop that is configured to stabilize the slave frequency of the slave laser with respect to the master frequency, the slave frequency being offset with respect to the master frequency successively, over time, by a first preset offset value, a second preset offset value, and a third preset offset value, the offset values being comprised in an interval equal to half the fundamental frequency difference plus or minus a few hundred MHz.