The dawn of photonic fiber-optic gyroscopes – An interview with KVH

High-end inertial units are one of the key components in aerial, naval and land systems, both commercial and military, for navigation, stabilization as well as other purposes. These systems typically include accelerometers, gyroscopes or a combination of both, while sometimes they are combined with magnetometers and Global Navigation Satellite System/Global Positioning System (GNSS/GPS) antennas. Inertial systems are characterized by the technology of the gyroscope used. But actually the market has passed through different technological stages, in almost 20-year technology cycles from first application to maturity. Initially, mechanical gyros appeared, and then optical ring laser gyroscopes (RLG) and fiber-optic gyroscopes (FOG) followed. Later came hemispheric resonator gyros (HRG) and MEMS.

FOG-based systems have great reach in various tactical and navigation-grade applications, following behind RLG, as well as some industrial-grade applications. The FOG market is currently worth more than $650M, according to Yole Développement (Yole)’s High-End Inertial Sensors for Defense, Aerospace and Industrial Applications Report 2020.
Integrated solutions are also underway, driven by the need for smaller form factor in industry for autonomous-everything and in tactical grade applications. Examples include integrated photonic FOGs by KVH or integrated resonator FOGs by Honeywell and TeraXion. Silicon photonics could eventually do to FOG what MEMS did to mechanical gyros. Is there a photonic revolution under way?

To better understand the applications targeted and the move to photonic FOGs, Dimitrios Damianos, Technology and Market Analyst from Yole, interviewed Elizabeth Jackson, Chief Marketing Officer and Senior Vice President for Strategy for KVH, a well-known player in the high-end inertial FOG market.

Dimitrios Damianos (DD): KVH is known for its Fiber Optic Gyroscope (FOG) and FOG-based IMU solutions. Could you describe briefly the company’s history as well as the markets and applications that you target and you are strong in?

Elizabeth Jackson (EJ): KVH is unique in our ability to use innovative technology to make the complex simple. We offer autonomous-level accuracy with higher performance at lower cost for exacting precision requirements, and we provide assured navigation with uninterruptable navigation for mission-critical applications. KVH is vertically integrated and therefore we control the design and production process for our open-loop FOGs and FOG-based products, including Inertial Measurement Units (IMUs) and Inertial Navigation Systems (INSs). We are one of the few high-performance sensor manufacturers to have that end-to-end control. KVH creates its own optical fiber at a dedicated facility in the Chicago area, and we package our FOGs together with other sensors for advanced applications to create solutions that offer outstanding accuracy and excellent durability at a lower cost than competing systems. We have been a leading manufacturer in the fiber optic gyro industry since 1997, have produced more than 120,000 FOGs, and we have strong Intellectual Property (IP) in terms of our inertial technology. As we have shared publicly, we have developed breakthrough Photonic Integrated Chip (PIC) technology that will change the game in terms of performance. Our business is strong across a range of defense and commercial applications and in the growing autonomous-everything segment, with customers choosing KVH for applications including unmanned subsurface systems, driverless vehicles, pipeline inspection, aerial mapping, humanoid robots, and payload stabilization, among many others.

DD: Lockheed Martin recently selected a KVH FOG for a sensor suite in a fighter jet program. What are the different gyro requirements for such applications in terms of range, bias, in-run stability, resistance to shock, bandwidth, Size, Weight and Power (SWaP), and price? How are they different from other applications such as naval navigation or military vehicle navigation?

EJ: I can’t speak about detailed applications and specs for individual customers, but there are some consistent differences in requirements. For example, mission critical airborne applications tend to require the capability to operate across all performance metrics under the most extreme conditions for temperature and vibration. Vehicle ground navigation requires excellent scale factor, below 50 ppm, low noise, below 0.009 deg/rt-hr, and minimal bias instability below 0.02 deg/hr to maintain the most precise position accuracy required for safety and route planning. Subsea applications deploy a lower accelerometer range for improved resolution, small form factor due to the overall platform size, and very low noise and minimal bias instability due to longer term denial of support sensors.

DD: How have the last one to two years been for your high-end inertial business and what were the main drivers?

EJ: KVH has seen steady sales growth for our inertial products over the past two years for everything from the DSP-1750 gyro to the 1700-series of IMUs for use in many different unmanned platforms. Our production line continues to be robust, and we continue to staff multiple shifts at our FOG manufacturing facility. There are three primary drivers for this growth: One is the growth of the autonomous everything segment; the second is major programs for military applications and Assured Positioning, Navigation and Timing (APNT); the third driver is that KVH is uniquely positioned to deliver a range of performance across varied platforms at a more affordable price. We just completed a large quantitative survey that validated the preference for KVH products compared to leading competitors who have higher-performance but higher-priced products as well as a preference for KVH compared to lower-cost, lower-performance products like MEMS.

DD: You have been involved for a long time in the inertial business. What have been the major changes over the past decade in your business in terms of customer relationship, customized services and feedback of your customers?

EJ: Our customers trust KVH, and our relationships continue to deepen and expand, increasing our customer base as well as adding multiple programs within our existing customer base. KVH can offer customized services because we are vertically integrated, so it is very easy for us to scale and to meet different needs of the end user. That ability sets us apart. We’ve also seen the importance of the ease of integration, and while our competition may provide a single solution, KVH prides itself on providing documented test reports, a flexible user interface, and developers’ kits to speed up and facilitate integration so customers can get new platforms up and running more quickly. Perhaps the biggest change is just beginning to happen. Our PIC technology, which we have been developing for the past two years, is now moving to the production stage. Our PIC technology is truly disruptive, and unlike anything that has happened with gyro technology in the last 25 years, because it creates system-level improvements to reduce size, power, and cost. In your next report, you should have a photonic gyro section!

DD: We will probably have to! Could you tell us more about this PIC technology? What is the driver for this innovation and how things are moving? What are the difficulties, technological or otherwise, and what would be an acceptable technical performance in terms of bias, and stability and so on?

EJ: KVH developed PIC technology with the goal of replacing individual fiber optic components with planar optical chips. We have eliminated optical splices, polarizers, and couplers and consolidated multiple discrete components on the chip, increasing manufacturing yield and reliability. The benefit is a performance improvement and significant cost reduction for existing systems, including autonomous vehicle platforms. One performance advancement example is our ability to achieve very low insertion loss with a chip designed to support mass production with high reliability. KVH has made significant progress in our PIC technology. Last year, we announced that we had delivered working prototypes, and we will be announcing our first shipments of PIC-inside products very soon.

DD: On the applications side, autonomous vehicles, with Advanced Driver Assistance Systems (ADAS) or robotaxis, industrial robotics, autonomous guided vehicles (AGVs), are identified trends for inertial systems, especially in GPS-denied environments. What are your activities in those domains? Which are the technical requirements for robotaxis in terms of range, bias, in-run stability, resistance to shock, bandwidth, SWaP and price?

EJ: KVH has always had solutions for GPS-denied environments, and the demand continues to increase given the growth of autonomous everything. There are more GPS-denied environments than most people realize. If you think not only of mining, pipelines, and subsea but also picture an autonomous vehicle in an urban environment or on a highway surrounded by three Mack trucks or going through a tunnel. KVH FOGs and FOG-based products are already deployed or being evaluated in more than 30 autonomous vehicle platforms. That translates to hundreds of driverless vehicle prototypes on the road. We are in non-disclosure agreements (NDAs) with leading players ranging from disruptors to traditional Original Equipment Manufacturers (OEMs). Autonomous platforms rely on sensor fusion, with multiple sensors on board, such as cameras, LIDAR, GPS, and inertial. FOGs enable 1 cm positioning and precision navigation even when GPS is unavailable, so inertial solutions like those KVH offers are critical to the precision and safety requirements of this industry.
Top performance criteria for the autonomous car market include scale factor, angle random walk, and bias instability. These factors all contribute to a safer vehicle. Scale factor is crucial to the safe operations of an unmanned platform, and KVH FOGs provide a very low scale factor value, ensuring proper operation in environments such as a parking garage, a traffic rotary, or any repetitive loop where entrance and exit are critical to maintain lane designation. Angle random walk, or noise, is important because a very low noise floor, such as that provided by KVH FOGs, supports accurate navigation. Conversely, high noise translates to positional inaccuracy. Bias instability, or drift, is a key metric for maintaining position and delivering precise turning measurements that will then protect the occupants of the platform. KVH’s IMU error is a fraction of the error of a MEMS IMU. For example, where a MEMS IMU will be 7 meters off after 60 seconds, a KVH IMU will be only 0.5 meter off after 60 seconds. For autonomous vehicles specifically, price is clearly a factor when it gets to individual cars, but many autonomous vehicle platforms today are revenue-generating platforms. Construction and people movers, for example, can afford to pay for a high-performance inertial sensor.

DD: How do you feel about the competition between RLG and MEMS? FOGs seem to have a nice sweet spot to defend, what’s your view on that? Can FOGs be cost effective against MEMS?

EJ: Other technologies are generally either too expensive or too inaccurate, whereas FOG technology provides high accuracy at a low cost. Given that gyro technology is always cost versus performance, FOG technology is perfectly designed to be successful in the autonomous vehicle market. The level of performance is designed to ensure safe, accurate and reliable operation of the platform. RLG technology is typically higher performing, and with this comes added cost. MEMs technology performance is hindered in higher vibration environments, such as automotive and airborne applications. FOGs can certainly be cost-effective against MEMS. Autonomous-everything manufacturers and autonomous-vehicle manufacturers have told us they need redundancy, but if they choose MEMS, even with redundancy, they don’t get the accuracy they require. Our new PIC technology gives us far more flexibility on pricing to negate the price advantage of MEMS. PIC is rewriting the cost-performance tradeoff.

DD: What can we expect from your company in the next couple of years?

EJ: In the near term, KVH will roll out the PIC technology across our entire platform, and we continue to work tirelessly to improve performance for all applications. The combination of being vertically integrated and having the PIC technology gives us the capability to provide a much broader range of performance across our product portfolio, including lower-end, modest, and high-end applications for incremental business opportunities. KVH is committed to being the leading provider of high-performance inertial products through superior design, manufacturing, reliability, and ease of integration for unmanned and autonomous platforms.

Elizabeth Jackson joined KVH in November 2017 as chief marketing officer and senior vice president for strategy. Prior to joining KVH, Ms. Jackson was CMO at DOTS Technology Corp, an NEA portfolio company in health tech, building a novel protein detection platform for consumer and industrial use. Ms. Jackson held CMO positions at HookLogic, a Bain Capital portfolio company in ad tech performance marketing that successfully sold to Criteo, and Summer Infant, a publicly traded durable goods company. She was head of Playtex Baby, vice president at The First Years, and held various positions at the start of her career at Campbell Soup Company and Procter & Gamble. Ms. Jackson received a B.A. from Princeton University and an M.B.A. from INSEAD in France.
More info: KVH Photonic Chip Technology

Dimitrios Damianos, PhD joined Yole Développement (Yole) as a Technology and Market Analyst and is working within the Photonics, Sensing & Display division.
Dimitrios works with his team every day to deliver valuable technology and market reports regarding the imaging industry including photonics and sensors.
After Master’s level research on theoretical and experimental quantum optics and laser light generation, Dimitrios pursued a Ph.D. in optical and electrical characterization of dielectric materials on silicon with applications in photovoltaics and image sensors, as well as Silicon-On-Insulator for microelectronics at Grenoble University, France.
In addition, Dimitrios holds a MSc degree in Photonics from the University of Patras, Greece. He has also authored and co-authored several scientific papers in international peer-reviewed journals.