Learn the Fundamentals of Light Detection

Learn the Fundamentals of Light Detection

Great optical systems start with a solid understanding of how light detection actually works. GPD Optoelectronics are excited to share their “Fundamentals of Light Detection” guide. This is a free resource designed to help engineers build confidence in photodiode selection and integration.

This guide covers semiconductor physics, PN junction behavior, and all major detector types, including PIN, APD, and Schottky designs, with material comparisons across silicon, germanium, and InGaAs.

Specialized geometries such as quadrant cells, tetralateral position-sensing detectors, and sandwich detectors for two-color detection are explained, along with circuit design guidance on transimpedance amplifiers, noise mitigation, and biasing strategies.

From fiber optics and LiDAR to spectroscopy and industrial sensing, this guide gives you the foundation to design with confidence across a 250 nm to 2.6 µm detection range.

Here’s what you’ll learn:

• A clear five-step framework for matching the right detector to your application
• The differences between PIN, APD, and Schottky detector designs
• When to choose silicon, germanium, or InGaAs, based on your wavelength range
• How to match detector material, geometry, and operating mode to the application
• How to evaluate speed, sensitivity, and environmental requirements together
• How to minimize key noise sources in photodetector circuits

About GPD Optoelectronics

Founded in 1973, GPD Optoelectronics began by making high-quality germanium transistors, but since the early 1980s the company manufactures both germanium and indium gallium arsenide photodiodes and multi-element photodetectors. In addition to offering a variety of off-the-shelf products, GPD specializes in providing customized parts that are uniquely tailored to customer applications. GPD has the agility to design and deliver prototypes of custom products often within just a few weeks.

GPD’s products include:

• Photodiodes
  • Germanium photodiodes
  • InGaAs photodiodes (standard, extended, high-speed)
  • Avalanche photodiodes
• Position sensing photodiodes
  • Multi-cell photodiodes (quadrant, octo^TM)
  • Tetralateral photodiodes
• Specialty photodiodes
  • Two-color detectors
  • Low-polarization-dependent-loss InGaAs photodiodes
• Packaging Options
  • Fiber coupling
  • Mounting configurations
  • Optical filters and coatings
  • Optical windows and lenses
  • Thermoelectric cooling
• Multi-Cell Photoreceiver (MCPR) Development Kits

To request more information or a quotation for these or other GPD products, contact IL Photonics.