Thinned Silicon Wafer Optical Filter with Thermal Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical communication systems face challenges in efficiently filtering optical signals across different frequency ranges, leading to performance issues and errors in signal processing.
Innovation Solution
An adjustable optical filter is developed using a thinned silicon wafer with an optical coating and integrated thermal tuning components, including ring heaters and thermistors, to adjust the passband frequency range by modifying the temperature of the silicon wafer, thereby filtering optical signals effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a silicon wafer is used as the base for an adjustable optical filter, then the filter can be thermally tuned to adjust the passband frequency spectrum, but the device requires complex thermal management components (ring heaters, thermal contact pads, thermistors) which increases device complexity
Solution Approach 1:
The patent combines multiple thermal management functions (heating via ring heater, thermal conduction via contact pads, and temperature sensing via thermistors) into an integrated thermal management system directly coupled to the silicon wafer, allowing coordinated control of temperature for frequency spectrum adjustment while reducing the need for separate discrete components
Solution Approach 2:
The patent adjusts the passband frequency spectrum by changing the temperature parameter of the silicon wafer through the integrated thermal management components, enabling dynamic tuning of the optical filter's frequency response without mechanical movement or structural changes
2Reliability
If the silicon wafer is thinned to a particular thickness based on the passband frequency spectrum, then the filtering performance is optimized, but the manufacturing precision requirements increase significantly
Solution Approach 1:
The patent incorporates thermistors that monitor the temperature of the silicon wafer and provide feedback to the control system, which then adjusts the heating power to the ring heater to maintain the desired temperature and passband frequency spectrum, compensating for variations in wafer thickness
Solution Approach 2:
Instead of relying solely on precise mechanical thickness control, the patent uses temperature as a compensating parameter to adjust and optimize the filtering performance, allowing thicker or thinner wafers to achieve the desired spectral characteristics through thermal tuning
3Reliability
If ring heaters and thermal contact pads are integrated with the silicon wafer die, then temperature control is improved for frequency adjustment, but the ease of manufacture decreases due to additional integration steps
Solution Approach 1:
The patent divides the thermal management system into distinct functional segments (ring heater, thermal contact pads, thermistors) that can be independently fabricated and then integrated onto the silicon wafer, allowing each component to be optimized separately while maintaining overall system performance
Solution Approach 2:
The patent replaces mechanical thermal control methods with integrated electrical heating elements and electronic temperature sensing, eliminating the need for complex mechanical thermal management mechanisms and simplifying the overall manufacturing process
4Adaptability or versatility
If the adjustable optical filter is thermally isolated from the substrate using an adjustable optical filter sub-assembly, then frequency spectrum adjustment is enabled, but the device complexity increases due to the sub-assembly structure
Solution Approach 1:
The patent extracts the thermal management components from direct integration with the substrate and places them on the silicon wafer die itself, with the entire die assembly then mounted on the substrate, simplifying the overall structure by reducing the number of intermediate thermal isolation layers and components
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 enhances the filtering performance of optical communication systems by allowing precise adjustment of the frequency range, reducing errors, and improving signal processing efficiency.
Implementation Method 1
a ring heater integrated with the silicon wafer die. The ring heater may adjust a temperature of the silicon wafer die based on an electrical signal
Implementation Method 2
an optical coating disposed on a first surface of the silicon wafer die. The optical coating may filter an optical signal and may be based on the passband frequency spectrum
Implementation Method 3
a thermistor integrated with the silicon wafer die. The thermistor may monitor the temperature of the silicon wafer die
Implementation Method 4
a thermal contact pad integrated with the silicon wafer die and coupled to the ring heater. The thermal contact pad may receive the electrical signal and pass the electrical signal to the ring heater
Data Source
AI summary
A method may include thinning a silicon wafer to a particular thickness. The particular thickness may be based on a passband frequency spectrum of an adjustable optical filter. The method may also include covering a surface of the silicon wafer with an optical coating. The optical coating may filter an optical signal and may be based on the passband frequency spectrum. The method may additionally include depositing a plurality of thermal tuning components on the coated silicon wafer. The plurality of thermal tuning components may adjust a passband frequency range of the adjustable optical filter by adjusting a temperature of the coated silicon wafer. The passband frequency range may be within the passband frequency spectrum. The method may include dividing the coated silicon wafer into a plurality of silicon wafer dies. Each silicon wafer die may include multiple thermal tuning components and may be the adjustable optical filter.