1:1 with Jigesh Patel

Embracing Photonics Applications in Aerospace and Defense

We sat down with Jigesh Patel, Technical Marketing Manager of AMS Simulation at Synopsys, to learn the challenges and benefits of using photonics in A&D systems. 

Q: Can you please tell us why there is an immense amount of interest these days in adopting photonics and fiber-optics in wide-ranging applications, including Aerospace and Defense?

You’re right – photonics and fiber-optics are on the rise, and some believe we are experiencing an optical “mega-cycle.” Dramatic explosion of data, cloud services and Internet traffic have exposed the bandwidth limitation of copper which is why you see single-mode fibers rapidly replacing copper almost in every interconnect technology. In addition to the favorable economics from higher energy efficiency, smaller footprint, enhanced reliability and lower cost, photonic integration is recognized as essential to national security. In 2015, the US Department of Defense (DoD) launched a public-private investment initiative and created an American Institute for Manufacturing Integrated Photonics (AIM Photonics). In 2018, Congress committed $1.2 billion to fund activities promoting quantum information science (QIS). Photonics is a key enabler to quantum computing, quantum communication and cryptography for civilian and ISTAR (intelligence, surveillance, target acquisition and reconnaissance) applications. 

Q: What are the challenges and benefits of using photonics in Aerospace and Defense systems?

Traditionally, A&D communication infrastructure is wireless and copper dominant. There’s a wealth of in-house RF expertise, while photonics R&D within A&D sector is on the rise only recently. Ultra-high-resolution aerial and satellite imaging, large amount of data from sensor networks, real-time simulation and computation needs, secure communication, on-board high-speed Internet and entertainment are some of the reasons where existing RF and copper-based infrastructure is no longer enough. Optical fibers offer much higher bandwidth, provide significant weight-savings (a critical need in aerospace), require much lower maintenance, provide higher durability and reliability. Photons travel much faster than electrons, which is why latency in fiber-optics is minimally low. In Figure 1 we see a comparison of copper and optical fiber. Unlike copper-based systems, fiber-optics consumes less energy, generates no heat, offers excellent protection against fire, and provides immunity from RF-interference and eavesdropping. In addition, the wireless RF-spectrum is scarce and heavily regulated, while the photonic spectrum is vast and free from regulatory or compliance obligations. 

Figure 1 – Copper vs. optical fiber 

Q: What photonics solutions does Synopsys offer?

Synopsys offers industry’s broadest photonic design products portfolio as shown in Figure 2. This portfolio can be categorized into three functional groups: (i) photonic device design (ii) photonic systems design and (iii) photonic ICs design. RSoft Photonic Device Tools offer simulation for active (such as lasers, VCSELs, modulators) and passive (such as waveguides, fibers, gratings, resonators, etc.) photonic devices. OptSim is an award-winning fiber-optic and free-space optical systems and circuit simulator. OptoCompiler is industry’s only unified electronic and photonic IC design platform. 

Figure 2 – Photonic tool offerings from Synopsys 

Q: How do these solutions support the Aerospace and Defense Market?

Aerospace and Defense system developers and users are investigating and adopting photonics in land, sea, air and space systems. Fibers are clearly valuable for moving data in a number of ways:

  • From data center to edge, as part of the network infrastructure
  • Between sensors in the field and central processing facilities and command centers
  • For data communications in embedded applications, such as from a sensor to the sensor processing, such as a Radar on a ship
  • For novel use in embedded systems, such as in the example of the fiber optic gyroscope

As mentioned above, Synopsys provides tools and capabilities for design and simulation of fiber-optic systems, electronic-photonic circuits, active and passive photonic devices, and nanoscale optical structures that are of interest to the A&D industry. The tools support interfaces with Synopsys and third-party tools, offer advanced Monte Carlo and corner analyses capabilities, parameter scanning, advanced visualization, and optimization options.

Figure 3 –  Synopsys end-to-end electronic-photonic co-design solution 

Q: Can you provide a couple of example applications and how the Synopsys photonic design tools benefit customers?

Sure. RF-over-fiber is a choice of high-speed data transmission in uplink and downlink satellite communications. It is shown pictorially in Figure 4. Designers of such links need to consider complex trade-offs involving interplay of noise, sensitivity, bandwidth, dynamic range and linearity of the link. For the transmit side perspective, link linearity and high RF output power over wide bandwidth are more important than noise. On the other hand, for the receiving side perspective, low noise and high dynamic range are more important. OptSim, Synopsys fiber-optic and free-space optic system design tool, is an ideal tool for rapid prototyping of RF-over-fiber systems.

Figure 4 –  Schematic of a satellite downlink with RF-over-fiber. RF-over-fiber can also be used in satellite uplinks end-to-end electronic-photonic co-design solution 

In Figure 5 Photonic and fiber-optic sensors are attractive alternatives to their mechanical counterparts in A&D due to the former typically having a smaller number of moving parts (and hence lower maintenance), immunity from RF interference and smaller size/lower weight perspective. Interferometric fiber-optic gyroscope (iFoG) is rapidly replacing mechanical gyroscopes for navigational and attitude control in aerospace because (i) it is compact and light-weight, (ii) it has no moving parts (i.e., quick startup), (iii) it is much less sensitive to temperature, vibrations and shocks (iv) is maintenance-free and (v) offers better durability/longer life. However, designing an iFoG sensor system requires advanced analyses of Sagnac, Monte Carlo and polarization reciprocity effects. Synopsys OptSim is the right tool for this type of design, and it comes with a rich library of components and visualization options.

Figure 5 –  Designing an iFoG in OptSim 

Q: How does this benefit commercial aerospace customers?

The commercial aerospace industry can benefit from the advantages of photonics and fiber-optics as mentioned earlier: improved performance, SWaP, reliability, operational cost and more. Modern commercial aircrafts have between 70 to 300 miles of copper cables on average which can weigh approximately anywhere between 1750 to 7000 pounds. While not all copper cables can be replaced by fiber, replacing communication cables by fiber and photonics can go a long way towards reduction in weight and size while improving thermal, energy and spectral efficiencies. A Military and Aerospace Electronics article and a blog from ‘Fulfillment by ASAP’ discussed a 25% size improvement and 50% weight savings. Synopsys photonic design tools offer productivity gains through automation and an exceptional value in designing avionic fiber-optic links and photonic integrated circuits.     

Q: Thank you Jigesh for joining us for this insightful discussion. Any closing remarks?

You’re welcome! Synopsys photonics design solutions are the industry standard and,…we think…, the best. Please register with our A&D newsletter, check our Synopsys photonics website, and reach out to your local Synopsys account manager for more information.