Photonic Modulator Design and Simulation Using Ansys Lumerical
Hello, ladies and gentlemen. Thank you for joining this webinar. Today, I will be discussing the method of designing and simulating a photonic modulator using Ansys Lumerical. My name is Majid, and I am a technical manager at Ozen Engineering, Inc. My main research focus is on silicon photonics, as you can see in my Google Scholar profile.
About Ozen Engineering, Inc.
Ozen's headquarters is located in Sunnyvale, and you can see the various branches of Ozen Engineering on the map. At Ozen Engineering, we specialize in the simulation of optics, photonic structures, thermal fluid, and electromagnetic fields. We are an Ansys Elite Channel Partner, offering Ansys software consulting, training, mentorship, and technical support.
Outline of the Talk
- Discuss optical transceivers.
- Delve into the optical modulator part of optical transceivers.
- Compare three types of modulators: Electro-Absorption Modulator, Mach-Zehnder Modulator, and Micro-Ring Modulator.
- Demonstrate how to create and simulate these modulators using Ansys Lumerical tools at both component and circuit levels.
Silicon Photonics and Optical Transceivers
Optical transceivers are crucial for data and telecom. The roadmap for silicon photonics indicates a need to reach 25.6 or 51.2 terabits per second by 2025 with co-packaged optics. The demand for such bandwidth arises from cloud services, industrial automation, video streaming, and emerging technologies like augmented reality, virtual reality, connected cars, and the Internet of Things.
Key Trends in Optical Transceiver Technology
Companies like Cisco have developed photonic electronic circuits. For example, a photonic electronic chip includes:
- An electronic IC
- Silicon photonics (blue component)
- A light source and fiber array
Regarding co-packaged optics, companies like Intel and Rockley Lab are actively working in this area. The key trends include:
- Pluggable Optics: Offers multi-vendor support and flexibility but faces limitations due to power and electron mobility.
- Onboard Optics: Expected to achieve 3.2 terabits per second by 2027.
- Co-Packaged Optics: Especially in silicon photonics, expected to achieve 6.4 terabits per second by 2030.
Optical Modulators
Optical modulators are essential for photonic transceivers. They include electronic and photonic chips, with drivers compatible with CMOS. The main types of modulators are:
- Electro-Absorption Modulator: High bandwidth, low driver swing, low thermal sensitivity, but limited to the O-band.
- Mach-Zehnder Modulator: High driver swing and area, suitable for applications not requiring compact devices.
- Micro-Ring Resonator: Good modulation driver sync but sensitive to thermal changes.
Electro-Absorption Modulator
The physics behind the electro-absorption modulator is the quantum confined Stark effect. It involves materials like indium gallium arsenide and gallium arsenide, forming a heterostructure semiconductor. Applying voltage tilts the band, shifting excitonic peaks and enabling modulation.
Design Workflow with Ansys
- Start with Ansys Mode to calculate effective index and overlap with the gain region.
- Use Numerical Charge to calculate absorption coefficient and transmission as a function of applied bias voltage.
- Connect components in Numerical Interconnect to calculate modulation response.
Simulation Tools
The simulation involves using Ansys Lumerical tools such as Numerical Mode, Charge, and Interconnect. These tools allow for the design and analysis of photonic modulators, including:
- Defining materials and geometry
- Setting up solvers and simulation parameters
- Analyzing results and optimizing designs
Conclusion
If you have any questions or need support, feel free to contact us at support@ozeninc.com. Thank you for attending this webinar.
Hi ladies and gentlemen, thank you for joining this webinar. Today, I'm talking about the method of designing and simulating photonic modulators on numerical software. My name is Majid, I'm a technical manager at Ozen Engineering. My main research is focused on silicon photonics.
At Ozen Engineering, we are experts in the simulation of optics, photonics, structural, thermal, fluid, and electromagnetic fields. We are an Ansys Elite Channel Partner, offering Ansys software, consulting, training, mentorship, and technical support.
The outline of my talk: first, I will discuss optical transceivers, then I will focus on the optical modulator part of optical transceivers, and compare three modulators: electro-absorption, Mach-Zehnder, and micro-ring.
I will then show you how to create and design these modulators using Ansys tools, both at the component and circuit levels. Regarding silicon photonics, the optical transceiver is part of data and telecom.
The roadmap for silicon photonics shows that by 2025, we need to reach 25.6 or 51.2 terabit per second with co-packaged optics.
The demand for such high bandwidth is due to cloud services, industrial automation, video streaming, and emerging technologies like augmented reality, virtual reality, connected cars, and the internet of things.
To achieve this high bandwidth, some companies have created photonic electronic circuits. For example, Cisco has created a photonic electronic chip, where the electronic IC is combined with silicon photonics and a light source and fiber array.
In co-packaged optics, companies like Intel and Rockley Lab are working on integrating IC and silicon photonics. The key trend for optical transceiver technology is pluggable optics, which supports multi-vendor flexibility but has limitations due to service power.
The trend is to achieve 1.6 terabits by 2025, but increasing the bandwidth beyond that is difficult due to the nature of electronics.
For this reason, we need to move towards onboard optics, which is expected to achieve 3.2 terabit per second by 2027. However, co-package optics, especially in silicon photonics, can dominate these barriers and achieve 6.4 terabit by 2030. The optical transceiver I'm talking about today is focused on this area.
Intel optical IO is an example of a co-package optics technology made from silicon for data optimization. In 2020, Intel demonstrated a 1.6 terabit pluggable module, while in 2016, they had a 100 gigabit per second pluggable module.
This increase in bandwidth is due to the photonics and electronic circuits being fabricated near each other, reducing the size of electrical paths. Now, let's talk about photonic transceivers. A photonic transceiver consists of a laser, modulators, a transmission medium, and photodetectors.
The modulator converts an electrical signal to an optical signal, which is then converted back to an electrical signal by the photodetector. Today, we will focus on photonic modulators. Optical modulators have merits of interest for certain applications.
In electronic chips, we have a driver that must be compatible with CMOS. In photonic chips, we have limitations in bandwidth and optical modulation amplitude. We are working to improve these characteristics numerically.
Regarding different modulators, electro-absorption modulators have a high bandwidth, low driver swing, and low thermal sensitivity, but they cannot be used in the O-band.
Mach-Zehnder modulators have a high driver swing and large area, making them suitable for applications where compactness is not a concern. Micro-ring resonators have a high modulation driver swing but are sensitive to thermal effects. Electro-absorption modulators use quantum confined Stark effects.
When a voltage is applied, the excitonic peaks shift to longer wavelengths due to the electrons being attracted to the positive holes and the holes going to the negative holes. The extension ratio of electro-absorption modulators depends on the confinement factor and absorption coefficient.
We can calculate these parameters using numerical tools. To model electro-absorption modulators, we can use quantum dots, quantum wells, or graphene. When a voltage is applied, the excitonic peak is removed or shifted using excitonic effects.
The workflow for designing electro-absorption modulators with Ansys involves calculating the effective index and overlap with the gain region in numerical mode, calculating the modal properties like effective index, group index, and mode confinement in numerical charge, and calculating absorption coefficient and transmission as a function of applied bias voltage in numerical charge.
In numerical interconnect, we can connect this component together and calculate the modulation response. Thank you for watching. If you have any questions about numerical mode, numerical charge, or numerical interconnect, please let me know. You can contact us at ozeninc.com for support. Thank you.
