Hybrid Integrated Laser With Arrayed Waveguide Grating Tuning
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Solution Overview
Problem
Conventional tunable lasers face challenges in achieving broad tuning range, stability, and miniaturization while maintaining low power consumption and high integration level, with monolithic integrated semiconductor lasers being complex and costly to produce, and external cavity adjustable lasers having poor stability due to multiple components.
Innovation Solution
An arrayed waveguide grating based hybrid integrated laser is developed by coupling end surfaces of a semiconductor gain die and an arrayed waveguide grating based optical waveguide chip, incorporating an arrayed waveguide reflection-controllable component to adjust loss and reflection characteristics, enabling wavelength tuning and improving integration and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a monolithic integrated semiconductor tunable laser is used, then the volume is small and stability is good, but the fabrication process is very complicated and cannot be mass produced with low cost
Solution Approach 1:
The laser system is divided into separate functional modules: a semiconductor gain chip for light generation and a silicon-based optical waveguide chip for wavelength selection and external cavity formation. This segmentation allows each module to be optimized and fabricated independently using appropriate processes, avoiding the complexity of monolithic integration while maintaining compact size and stability.
Solution Approach 2:
The complex grating structure and external cavity components are extracted from the semiconductor gain chip and implemented separately on the silicon-based optical waveguide chip. This extraction simplifies the fabrication process by allowing the gain chip to be manufactured using standard semiconductor processes while the optical waveguide chip is fabricated using silicon-based processes.
2Adaptability or versatility
If a conventional external cavity adjustable laser is used, then the tuning range is large and line width is narrow, but the volume is relatively large and miniaturization is difficult
Solution Approach 1:
The mechanical diffraction grating in conventional external cavity lasers is replaced with an integrated arrayed waveguide grating on a silicon-based optical waveguide chip. This substitution eliminates the need for large mechanical components and moving parts, enabling miniaturization while maintaining the broad tuning range and narrow line width characteristics.
Solution Approach 2:
The external cavity components including the arrayed waveguide grating and resonance cavity are nested within the compact silicon-based optical waveguide chip structure. This nesting allows the external cavity functionality to be integrated into a small footprint, dramatically reducing the overall laser volume while preserving the desired optical performance.
3Volume of moving object
If a micro-mechanical tuning device is used, then the volume is greatly reduced and tuning speed is high, but the stability is poor
Solution Approach 1:
Mechanical tuning components are replaced with an electrically controlled arrayed waveguide grating on a silicon-based optical waveguide chip. The wavelength tuning is achieved by electrically switching between different waveguide paths in the arrayed grating structure, eliminating mechanical moving parts while maintaining small volume and high tuning speed. The integrated photonic structure provides inherent mechanical stability and resistance to environmental perturbations.
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 provides a tunable laser with good stability, narrow line width, and ease of integration, facilitating mass manufacture and reducing complexity and cost, while overcoming the limitations of conventional external cavity adjustable lasers.
Implementation Method 1
an arrayed waveguide grating optically connecting the plurality of controllable devices to the semiconductor gain die
Implementation Method 2
Each of the plurality of the controllable devices can change in-cavity loss of the resonant cavity or change reflection characteristic of the reflection end of the optical waveguide chip
Data Source
AI summary
An arrayed waveguide grating based hybrid integrated laser has an adjustable external cavity. The waveguide includes a semiconductor gain die and an optical waveguide chip. The optical waveguide chip includes an arrayed waveguide grating and an arrayed waveguide reflection-controllable component. A resonant cavity is formed by the output end reflection-controllable arrayed waveguide grating chip and the semiconductor gain die. An output wavelength of the laser can be adjusted by changing a driving condition of the reflection-controllable component. The output wavelength is determined by a center wavelength of each channel of the arrayed waveguide grating.