VCSEL Driver Layout for Low-Delay LIDAR Pulse Control
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Solution Overview
Problem
In LIDAR systems, the separate mounting of laser diode drivers (LDD) and vertical cavity surface emitting lasers (VCSEL) leads to long wiring lengths, causing delays and waveform distortions due to wiring impedance and inductance, particularly at high frequencies, which affects the accuracy of time-of-flight measurements.
Innovation Solution
A semiconductor laser driving apparatus with multiple laser diode drivers disposed around or under the VCSEL, connected via capacitors and micro lens arrays, to reduce wiring length and improve light emission pulse control, using a fan-out wafer level package with heat dissipation and external terminals for efficient thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If laser diode drivers and VCSEL are mounted separately, then ease of manufacture is improved, but wiring length increases causing delay and waveform distortion
Solution Approach 1:
The patent combines the laser diode driver and VCSEL into a single integrated package structure, where the driver is mounted on the same substrate as the VCSEL. This merging eliminates the need for external wiring connections, thereby reducing wiring length and associated delays while maintaining ease of manufacture through standardized packaging processes.
Solution Approach 2:
The patent introduces a substrate as an intermediary component that hosts both the laser diode driver and the VCSEL in close proximity. This substrate acts as a mediator that provides electrical connections and mechanical support, enabling short wiring paths while facilitating standardized manufacturing processes.
2Device complexity
If laser diode drivers and VCSEL are mounted separately, then device complexity is reduced, but waveform distortion increases due to wiring impedance and inductance
Solution Approach 1:
By integrating the driver and VCSEL in a single package, the patent eliminates external wiring connections that introduce impedance and inductance. This merging maintains signal integrity and reduces waveform distortion while keeping the overall device structure relatively simple through standardized packaging.
Solution Approach 2:
The patent optimizes the local wiring environment by placing the driver and VCSEL in close proximity on the same substrate. This local arrangement minimizes the wiring path length and reduces the impact of wiring impedance and inductance, thereby improving waveform accuracy without significantly increasing overall device complexity.
3Measurement precision
If wiring length is reduced by integrating driver and VCSEL, then light emission pulse accuracy is improved, but manufacturing complexity increases
Solution Approach 1:
The patent integrates the driver and VCSEL in a standardized package structure that achieves short wiring lengths and high pulse accuracy. This merging is implemented using conventional packaging techniques, thereby minimizing increases in manufacturing complexity while maximizing measurement precision.
Solution Approach 2:
The patent optimizes key parameters such as wiring length, wiring layout, and electrical connection geometry within the integrated package to achieve high light emission pulse accuracy. These parameter optimizations are implemented within standard manufacturing capabilities, balancing precision requirements with manufacturing complexity.
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
This configuration significantly reduces wiring length and delay, enhancing the accuracy of light emission pulses and improving the performance of LIDAR systems by minimizing waveform distortion and increasing the detection range.
Implementation Method 1
a vertical cavity surface emitting laser (VCSEL) that emits laser light in pulses
Implementation Method 2
the light being formed into a beam by a light-emitting lens system
Implementation Method 3
a light-receiving unit that receives, by the light receiving lens system, reflected light beams from the subspaces and forms images of the reflected light beams on the light-receiving elements
Implementation Method 4
using a fan-out wafer level package with heat dissipation and external terminals for efficient thermal management
Data Source
AI summary
Provided is a semiconductor laser driving apparatus of a division emission scheme which reduces a delay of a light emission pulse due to an influence of a wiring length of a light-emitting element of a VCSEL located far from an LDD, and a vehicle control system including the semiconductor laser driving apparatus. The configuration includes a vertical cavity surface semiconductor laser (10) having a plurality of light-emitting elements (13), and at least two or more laser diode drivers (20) disposed around the vertical cavity surface semiconductor laser (10) and having a plurality of driving elements that is connected to the light-emitting elements (13) from a peripheral surface of the vertical cavity surface semiconductor laser (10) and causes the light-emitting elements (13) to emit light.