Miniature Laser Grown on Silicon Chip

17.04.2025

Miniature Laser Grown on Silicon Chip

Why in the news?   

Scientists from the US and Europe have successfully fabricated miniature lasers directly on silicon wafers, as published in a recent study in Nature.

About Miniature Laser Grown on Silicon Chip

• This is a major advancement in the field of silicon photonics, as integrating a light source (laser) directly on the chip has long been a technological challenge.
• Traditionally, lasers are manufactured separately and then attached to chips, which results in slower operation, higher costs, and manufacturing mismatches.
• The new research resolves this issue by growing the laser directly on a silicon chip using a scalable process and compatible with standard CMOS (Complementary Metal-Oxide-Semiconductor) technology, which is the backbone of current semiconductor manufacturing.
• Initially, electrons carried data within silicon chips. However, modern advancements are replacing electrons with photons, leading to the rise of silicon photonics.
• Photons carry information faster, with higher bandwidth and lower energy loss than electrons, making them ideal for next-generation computing, especially in data centres, sensors, and quantum computing.

Photonic Chip Components and Laser Physics

• A photonic silicon chip consists of four key parts:
  • A light source (laser),
  • Waveguides to channel the photons,
  • Modulators to encode or decode data onto light signals, and
  • Photodetectors convert light into electrical signals
• The laser functions on the principle of stimulated emission, where electrons drop to a lower energy level, releasing coherent photons to form a laser beam.

However, silicon has an indirect bandgap, making it inefficient at light emission. Therefore, materials like gallium arsenide (GaAs) with a direct bandgap are preferred for laser construction.

• The setup was completed with a protective layer of indium gallium phosphide and electrical contacts to power the laser.

                               Source: The Hindu

Scientists recently fabricated miniature lasers directly on which of the following material?

A.Graphene

B.Silicon wafers

C.Gallium nitride

D.Quartz

Answer B