Acousto-optic Directional Device for CMOS-Compatible Broadband Isolation
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Solution Overview
Problem
Conventional magnetic-free isolators and circulators have limited bandwidth and are not compatible with CMOS technologies, hindering full system integration in applications such as communication systems, LiDAR, and OCT, while integrated isolators and circulators for Si/SiN platforms are currently unavailable.
Innovation Solution
A broadband acousto-optic based directional optical device using a waveguide structure and a tunable array of acoustic wave transducers to induce momentum- and frequency-shifts in optical waves, enabling phase matching over a wider bandwidth, suitable for optical waves with wavelengths ranging from 200 nm to 2000 nm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional magnetic-free isolators and circulators are used, then CMOS compatibility is achieved, but bandwidth is limited
Solution Approach 1:
The patent replaces magnetic materials with acousto-optic interaction mechanisms. Specifically, it uses acoustic waves to modulate the refractive index of the waveguide, creating a moving grating that enables non-reciprocal light propagation without requiring magnetic materials, thus achieving both broadband operation and CMOS compatibility
Solution Approach 2:
The patent changes the physical mechanism from magnetic field interaction to acoustic wave interaction. By using acoustic waves with controllable frequency and amplitude to modulate the optical properties of the waveguide, the system achieves broadband operation while maintaining compatibility with standard CMOS fabrication processes
2Adaptability or versatility
If broadband operation is achieved, then wavelength range increases, but device complexity increases
Solution Approach 1:
The patent introduces dynamic control through acoustic wave modulation. The acoustic waves can be dynamically adjusted in frequency, amplitude, and phase to achieve broadband operation across different wavelengths. This dynamic approach allows a single device structure to operate over a wide wavelength range without requiring multiple static components
Solution Approach 2:
The acousto-optic waveguide structure serves multiple functions: it guides optical waves, modulates refractive index through acoustic interaction, and enables non-reciprocal propagation. This multi-functional design achieves broadband operation without proportionally increasing device complexity, as the same structural elements perform multiple roles
3Ease of manufacture
If integrated isolators and circulators are implemented, then system integration improves, but availability for Si/SiN platforms is currently unavailable
Solution Approach 1:
The patent replaces magnetic material-based isolators with acousto-optic devices that can be fabricated using standard CMOS processes. The acoustic waves are generated by piezoelectric transducers that can be integrated directly into the waveguide structure, enabling monolithic integration on Si/SiN platforms without requiring external magnetic components
Solution Approach 2:
The patent uses acoustic waves as an intermediary to achieve non-reciprocal light propagation. The acoustic waves mediate the interaction between the optical field and the waveguide structure, enabling isolator and circulator functions that can be integrated into CMOS-compatible platforms like Si/SiN, bridging the gap between optical functionality and semiconductor fabrication
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 achieves broadband operation, allowing for efficient control of optical wave propagation and directionality, suitable for optical isolators and circulators, and is compatible with CMOS technologies, enhancing system integration and performance in various applications.
Implementation Method 1
a broadband acousto-optic based directional optical device... generate a first plurality of acoustic waves... induce a momentum-shift and a frequency-shift in the first optical wave
Data Source
AI summary
The present disclosure relates to non-reciprocal/directional optical devices. The disclosure proposes a directional optical device, an optical system and a corresponding method of operating the optical system. The directional optical device comprises: a waveguide structure and an array of a plurality of acoustic wave transducers, wherein a first plurality of acoustic waves generated by the array is configured to induce a momentum-shift and a frequency-shift in a first optical wave propagating in the waveguide structure such that the first optical wave transitions from a first optical mode to a second optical mode, wherein the array is configured to establish a first set of phase differences between the first pluralities of acoustic waves. The array is tunable and/or the waveguide structure is tapered to change a wavevector of the optical wave in a first section of the waveguide structure such that the first optical wave transitions to the second optical mode.