SensL Interview: Solid state LIDAR reductions

Ahead of IS Auto Europe we interviewed Dr Carl Jackson, CTO and Founder of SensL on LIDAR sensor technology. Hear more from Carl Jackson this April during the ‘Cutting-edge sensor technologies" track on day one of IS Auto Europe, where his presentation will be on ‘Solid State LiDAR teardown: How do you build one for $250?’

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What makes SensL’s technology different to other LIDAR sensors out there?

Historically, LiDAR systems have been built with a variety of sensor types but the performance, cost and practical requirements for ADAS limit the number of available sensors that can be considered in practice.

Due to its low internal gain and hence limited signal to noise ratio (SNR), avalanche photodiodes (APDs) are limited to short-range LiDAR where the returned signals are brighter. SensL silicon photomultipliers (SiPM) have very high internal gain and therefore do not require external amplification that would contribute additional noise to the signal. Therefore, despite the lower PDE (photon detection efficiency) at 905nm, the SiPM will have a better SNR than the APD in many use cases.

In addition, the SiPM is sensitive to single photons, which allows the LiDAR to range to much greater distances and in harsh environments. It does this by identifying correlated photons through a multi-shot approach.


You are speaking on Solid State LIDAR and how to bring the price down to <$250 – why is this an important area of development as we move towards automated vehicles?

Most full LIDAR systems to date have been large and conspicuous, with impractical price-tags. To become part of the fusion of sensors required for practical ADAS, LiDAR systems will need to be more compact and significantly cheaper. Alongside these fairly obvious requirements are a host of other challenges that also need to be addressed such as laser power and stability, a large FoV and avoiding any moving parts.

It is important to note that a solid-state LiDAR is comprised of lasers, beam steering, optics, and processing in addition to the sensor.  It is really these critical components that enable this striking price capability.  A weak link in any of these elements can change the system requirements and cost.

With the SensL SiPM sensor, it will be possible to provide a completely solid state LiDAR (no moving parts) while addressing these other challenges, for under $250 per system.  We are excited to show you how we fit as the sensor for long range LiDAR.


What do you see as the biggest changes coming up in sensor development and its applications within automotive in the next 12-24 months?

There will be a lot of focus on practical proof of concept and stress testing it both in terms of its ability to deal with harsh environments, but also addressing the needs of auto qualification. There will be an increasing focus on systems that are fully solid state to avoid the issues of moving parts, and a big drive to lowering the cost of systems to a practical level.

For sensors another challenge is scaling production to meet the high volume automotive requirements and provide highly uniform devices.  Sensors that are built in CMOS (vs. other process technologies) are better suited to scalability due to the inherent capabilities of CMOS as compared to InGas or InP which are mostly used in low volume/high cost system applications.


Why do you feel it’s important to be part of IS Auto Europe 2017?

There are many companies looking to develop LiDAR modules as they grow their product portfolio to have a complete suite of sensors for ADAS.  The industry is very interested in understanding how to achieve the really challenging objective of identifying low reflective targets at long distances in a cost effective way.  Education events where we can share our experiences in studying this design challenge are important to us and the industry.

We would welcome attendees interested in learning more about ToF LiDAR and the design considerations to enabling long distance target identification to checkout a new video we produced on the topic.  A link is here: http://wvw.sensl.com/lidar_sensors