New 800G Silicon Photonic Engines for 800G-DR8 and LPO modules from Rain Tree

Created September 11, 2023
Technologies and Products

Silicon photonics chip maker Rain Tree Photonics Pte. Ltd. (RTP), has announced the availability of 800G silicon photonics-based solutions for 800G-DR8 and LPO optical modules. The 800G-DR8 solutions have already been validated in modules while validation is ongoing for LPO. RTP’s 800G silicon photonics engines come in two versions – a single chip version (RTP11008), in which each chip contains eight channels and a dual chip version (RTP1908-D-LD), in which each chip contains four channels.

The photonic engines are built on RTP’s proprietary high-performance silicon photonics integration platform which is uniquely differentiated and well known for its excellent reliability, high yield, ability to deliver in volume and lowest cost. In each chip, the entire photonic circuit is optimized for low optical insertion loss, allowing each laser to serve four channels, reducing overall cost and power consumption. Each chip also features large mode-field-diameter fiber and laser couplers that ensure high yield with standard packaging lines. Uprated laser input couplers capable of handling high continuous optical power levels demonstrate excellent long-term reliability even under extreme over-stress conditions.

Rain Tree Photonics’ RTP11008 and RTP1908-D-LD are part of a family of low-power, high-performance Silicon Photonic engines for 100G/lane applications. Both are functionally similar. RTP11008 integrates all 8 channels onto a single chip whereas RTP1908-D-LD integrates 4 channels onto a single chip. In 800G-DR8 applications, either a single RTP11008 chip or dual RTP1908-D-LD chips should be used. A single RTP1908-D-LD chip can also be used for 400G-DR4 applications. Both feature high-performance, low-drive silicon photonic modulators, working with differential drivers down to 2.4 Vpp, enabling compatibility with a wide range of modulator drivers. The ICs also include integrated photodetectors, low speed phase-shifters, large mode-field-diameter couplers and various low loss optical components.

A key feature of RTP’s 800G silicon photonics engine is compatibility with a wide range of modulator drivers. They can be driven by drivers integrated within the DSP or by external drivers, which provides greater design flexibility to RTP’s customers. Typical TDECQ values of less than 1 dB are achieved over the entire temperature range. RTP’s proprietary modulators also exhibit highly linear characteristics together with intrinsically high S21 bandwidth. This makes RTP’s modulators particularly suitable for linear drive or LPO applications.

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This article was written
by Peter Dykes

Peter Dykes is a independent telecoms and technology journalist who has over that last 30 years written for a wide range of B2B publications and companies. A former BT engineer, he specialises in networks and associated support systems. He is currently Editor of Optical Connections.