Measurement of Quantum Efficiency in Silicon Photonics

What is Silicon Photonics Quantum Efficiency?

Introduction

Silicon Photonics Quantum Efficiency (QE) is a key parameter that measures the performance of silicon photonic devices. It represents the ratio of the number of incident photons to the number of electrons (or photons) converted during the photoelectric process. This is a critical indicator of the efficiency of optical devices.

External Quantum Efficiency (EQE): The percentage of incident photons that successfully generate electrons (or photons).
Internal Quantum Efficiency (IQE): The percentage of absorbed photons that are successfully converted, reflecting the performance of the material and structure.

Measurement Methods

Below are common methods for measuring silicon photonics quantum efficiency:

1. Photodetector Measurement

A monochromatic light source with known power is directed at the detector, and the generated current is measured. External quantum efficiency is calculated using the formula:

EQE = (Detected Current ÷ Charge) ÷ (Incident Power ÷ Photon Energy)

2. Light Source Measurement

The light source is placed in an optical power meter to measure the emitted optical power. Simultaneously, the driving current is measured to calculate internal quantum efficiency.

3. Waveguide Structure Measurement

Photons are injected into a silicon photonic waveguide structure, and the absorption and conversion efficiency is estimated by comparing the output optical power of the waveguide to the incident optical power.

Applications

High quantum efficiency is critical for silicon photonics technology, widely used in data communications, optical sensing, and quantum computing. It is a key factor in improving the sensitivity and efficiency of devices.