Broadband Light Source – An Overview
Sensing has emerged as one of the most fascinating and essential fields for optical devices. With its widespread applications in clinical and other areas, more companies and individuals are stepping forward to research and develop new technologies in this sector. This blog discusses the Broadband Light Source (BLS) Modules, also known as SLD light sources, their characteristics, and applications.
What is a Broadband Light Source?
A Broadband Light Source is a device used for multi-wavelength tests and measurements of wavelength-division-multiplexing components. These light sources employ a broad spectrum of light, making them essential for evaluating the performance of optical networks and components across multiple wavelengths. They utilize the amplified spontaneous emission of diode-pumped, erbium-doped fibers, providing a broad range of wavelengths necessary for comprehensive testing and characterization.
Broadband Light Source Set
Most superluminescent diode light source sets consist of two types of equipment:
A. Broadband Light Source Modules
Superluminescent diode modules are small yet powerful sources of broad-spectrum light, often used for applications related to optical measurement and sensors, including OCT (Optical Coherence Tomography), gyroscopes, and other clinical applications. These modules are designed to provide a stable, wide wavelength range, crucial for detailed imaging and accurate measurements in various optical systems. They emit low-coherence light with a broadband spectrum like LEDs and high brightness like laser diodes. This combination enables high-resolution imaging and precise measurements. To ensure consistent performance and accuracy across varying environmental conditions, most SLD modules are stabilized.
B. Broadband Light Source Desktop
The BLS desktop, also known as the Remote Control Unit (RCU), is a device that allows users to monitor and read out the status of diodes. It provides a user-friendly interface for interacting with and managing the performance of various diode-based systems. This control unit offers features such as real-time status updates, configuration settings, and diagnostic tools to ensure optimal operation of the light sources.
The Principle of SLD Light Source
The emission of light in superluminescent diodes works on the same principle as laser diodes (LD) and light emission diodes (LED). Light emission occurs by flowing forward current to the p-n junction. When the power supply is connected, electrons flow from the n-side to the p-side, and holes move from the p-side to the n-side. This movement of charge carriers results in the recombination process, emitting light as a result.
Characteristics of SLD Module
- Superluminescent diode modules operate at different broadband emission wavelength ranges, between 670 to 1650 nm.
- These broadband light sources are ideal for applications requiring a reliable, powerful, and stable light source with broad-spectrum and low-coherence.
- Typically, SLD modules within the light source are powered by a high current & temperature controller.
- Superluminescent diodes offer low-speckle, broadband output.
- They have high directionality, limited diffraction (single spatial mode), high efficiency, and polarized output.
Diverse Applications of Superluminescent Diode Light Source
Broadband light sources have widespread applications in various industries. The primary applications of these benchtop instruments include:
- Optical fiber sensing: Utilizing a broad spectrum of light to detect changes in the properties of optical fibers.
- Optical metrology: Providing precise measurements of optical components and systems using a wide range of wavelengths.
- Biomedical imaging: Enabling high-resolution imaging techniques, including advanced medical diagnostic tools.
- Optical coherence tomography (OCT): Facilitating high-resolution imaging by using broad-spectrum light for detailed internal imaging.
- Fiber sensor interrogation: Assessing and analyzing the performance of fiber optic sensors.
- Passive component testing: Evaluating the performance and characteristics of optical components without introducing active elements.
- Spectroscopy: Analyzing the interaction of light with matter across a wide range of wavelengths to determine material properties.
With robust R&D efforts by various research centers and companies, many more SLD light source applications are expected to emerge soon.
Inphenix is a renowned photonic company that manufactures bright light sources, laser diodes, SWEPT lasers, and other products used in the clinical, telecom, sensing, and measurement industries. With industry experts and highly advanced technology, the company manufactures and supplies a wide range of customizable broadband light sources. These can be configured with SLDs as needed, providing tailored solutions to meet specific application requirements.
Their broadband light sources feature very short coherence length and high optical output power. In addition to ready-made superluminescent diodes and control units, the company offers standard light sources comprising powerful single or multiple SLDs. These can be used for extended spectral bandwidth, providing versatility in various high-precision applications.
