Fiber-Coupled Laser Apparatus for Rubidium Quantum Processor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser apparatuses for neutral atom-based quantum processors are complex, unreliable, and sensitive to vibrations due to numerous free-space coupled elements, leading to inefficiencies and the need for tedious realignment during transport.
Innovation Solution
A laser apparatus utilizing fiber-coupled Er-doped and Yb-doped DFB fiber lasers, combined with fiber-coupled SHG and DFG devices, to generate multiple laser beams for excitation of Rubidium atoms, reducing the number of free-space elements and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional free-space coupled laser elements are used, then multiple laser beams can be generated for atom excitation, but the device becomes complex and sensitive to vibrations
Solution Approach 1:
The patent combines multiple free-space optical elements into integrated fiber-coupled modules. The laser sources, modulators, and optical elements are merged into compact fiber-based assemblies that generate multiple laser beams (780nm, 840nm, 420nm, 1013nm) through a single fiber coupling interface, eliminating the need for separate free-space alignment of each component.
Solution Approach 2:
Optical fibers serve as intermediaries to transfer laser beams from the laser sources to the vacuum chamber. The fiber coupling acts as a mediator that replaces direct free-space optical paths, providing mechanical stability and vibration immunity while maintaining the required laser beam delivery functionality.
2Adaptability or versatility
If numerous free-space coupled elements are used, then multiple laser functions can be implemented, but reliability decreases due to vibration sensitivity
Solution Approach 1:
The patent replaces the mechanical free-space optical alignment system with a fiber-optic based system. Fiber optics inherently provide mechanical stability and immunity to vibrations, replacing the fragile mechanical alignment of mirrors, lenses, and beam paths that characterize traditional free-space laser systems.
Solution Approach 2:
Multiple laser functions (MOT, dipolar trapping, Rydberg excitation, Raman transitions) are combined into integrated fiber-coupled modules. Each module generates multiple laser beams at different wavelengths through a single fiber interface, consolidating what would traditionally require multiple separate free-space optical systems into unified reliable modules.
3Productivity
If free-space coupled elements are used, then laser beams can be generated for quantum processing, but realignment is required during transport
Solution Approach 1:
The patent replaces mechanical free-space optical paths with flexible fiber-optic connections. This substitution eliminates the need for realignment during transport, as fiber optic connections maintain their optical alignment regardless of mechanical movement or vibration, enabling the quantum processor to be transported and deployed without requiring optical realignment.
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 new laser apparatus simplifies the structure and significantly improves reliability by minimizing vibration sensitivity, ensuring robust operation and efficient beam generation for quantum processors.
Implementation Method 1
an Er-doped DFB fiber laser for emitting light at a wavelength of around 1560 nm; at least a first Yb-doped DFB fiber laser for emitting light at a wavelength of around 1090 nm
Implementation Method 2
a first fiber-coupled SHG device configured to receive light from said Yb-doped DFB fiber laser and to produce light at a wavelength of around 545 nm; a second fiber-coupled SHG device configured to receive a first part of said light from said first fiber-coupled DFG device and produce light at a wavelength of around 420 nm; a third fiber-coupled SHG device configured to receive a second part of light from said Er-doped DFB fiber laser and produce light at a wavelength of around 780 nm
Implementation Method 3
at least a first fiber-coupled DFG device configured to receive a first part of said light from said Er-doped DFB fiber laser and said light from said first fiber-coupled SHG device and produce light at a wavelength of around 840 nm
Implementation Method 4
Rubidium (Rb) atoms are introduced in a vacuum chamber and maintained in a predetermined volume of said chamber using a magneto-optical trap (MOT) comprising static magnetic fields and a plurality of MOT laser beams at a wavelength of about 780 nm. Such MOT laser beams aim at both reducing the kinetic energy of the atoms (i.e. their temperature) and, in combination with static magnetic fields, at introducing a restoring force that imposes the atoms to remain at a nearly fixed location.
Implementation Method 5
dipolar trapping is implemented in the vacuum chamber in order to trap individual atoms at different predetermined locations so that they can be individually addressed. More specifically, the atoms are arranged in an array of predetermined dimensions by creating a 1D, 2D, or 3D lattice of dipolar optical traps, each trap comprising at most one atom. Such lattice is generated by a dipolar trapping beam at a wavelength of about 840 nm
Implementation Method 6
The atoms are then prepared in a predetermined quantum state, for example a fundamental state, by using an optical pumping beam with a wavelength close to a resonance with a transition between quantum states of Rb atoms
Implementation Method 7
a so-called Rydberg excitation of Rubidium atoms in the vacuum chamber is implemented thanks to a two-photon transition scheme. In practice, a first and a second Rydberg beams at a wavelength of about 475 nm and about 795 nm, respectively (as disclosed, for example in [REF2]), or at a wavelength of about 420 nm and 1013 nm, respectively (as disclosed, for example in (REF3)), are sent to a predetermined number of atoms of the array to induce Rydberg transitions in said atoms
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
According to a first aspect, the present disclosure relates to a laser apparatus (210) for excitation of Rubidium (Rb) atoms in a quantum processor comprising an Er-doped DFB fiber laser (201) for emitting light at a wavelength of around 1560 nm; at least a first Yb-doped DFB fiber laser (202) for emitting light at a wavelength of around 1090 nm; a fiber-coupled laser source (203) for emitting light at a wavelength of around 1013 nm; a first fiber-coupled SHG device (301) configured to receive said light from said Yb-doped DFB fiber laser (202) and to produce light at a wavelength of around 545 nm; at least a first fiber-coupled DFG device (302) configured to receive a first part of said light from said Er-doped DFB fiber laser (201) and said light from said first fiber-coupled SHG device (301) and produce light at a wavelength of around 840 nm; a second fiber-coupled SHG device (303) configured to receive said light from said first fiber- coupled DFG device (302) and produce light at a wavelength of around 420 nm; a third fiber- coupled SHG device (304) configured to receive a second part of said light from said Er-doped DFB fiber laser (201) and produce light at a wavelength of around 780 nm, wherein said light at wavelength of around 780 nm is configured to produce MOT laser beams (111, 112, 113) for magneto-optical trapping of the Rb atoms and an optical pumping laser beam (120) for optical pumping of the Rb atoms; wherein said light at a wavelength of around 420 nm and said light at a wavelength of around 1013 nm are configured to produce Rydberg laser beams (141, 142) for transition of Rb atoms to Rydberg states.