CMOS Chip, Silicon Photonics For Efficient Transmitter

Researchers have developed a new transmitter using complementary metal-oxide-semiconductor, i.e., CMOS chip technology and silicon photonics, which achieved remarkable data transmission rates while consuming minimal energy. Integrating silicon photonics with electronics is essential for producing practical systems for numerous applications. The combination of the optical modulator and its electronic drive amplifier is a key electronic-photonic interface that often dictates system performance regarding speed and power consumption.

Initially, researchers tried to develop their transmitter using a conventional approach, which entails designing electrical driver amplifiers and optical modulators separately and then combining them. However, these methods yielded different results. Instead, they adopted an alternative method that involves co-designing the electrical driver amplifier and optical modulator inside the device. This approach allowed for a modeling methodology that incorporated all elements of the integrated transmitter.

The researchers created a transmitter with a relatively slow modulation to transmit data at high speeds. In initial tests, the device achieved a 112 gigabaud-112 gigabits per second on-off keying rate and a 224 gigabit per second pulse amplitude modulation. The device’s energy efficiency was below picojoules per bit, enabling high data throughput while reducing power consumption.

An alternative research direction in this area is integrating exotic materials with silicon waveguides for improved modulator performance. However, CMOS chip compatibility must be improved, complicating routes for high-volume, high-yield, and low-cost manufacturing. The new transmitter design introduced by the researchers could soon inspire the development of similar components to enhance communications.

Advanced CMOS chip design techniques could be used to fabricate photonics devices and build electronics and photonics devices as integrated functional modules. This convergence of photonics and electronics could enable device performance beyond standard electronics modules in speed, bandwidth, system complexity, and energy efficiency.

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