Optical Sensors

“Dark current” is a natural phenomenon that causes a small electrical current even when a photodiode detects no light. In well-designed photodiodes, this internally generated current is kept to a minimum. This improves the performance of the sensor by reducing noise and increasing the accuracy of light detection.

A variety of packaging options are available from TE Connectivity for surface mount devices (SMD) and through-hole devices (THD) to fit the most demanding applications.

TE Connectivity continues to develop robust sensor package designs and assembly procedures that enhance resistance to corrosive environments. Our sensors are designed to withstand harsh factory environments, helping manufacturers improve worker safety, reduce maintenance costs and increase productivity.

Our specialized global team and dedicated engineering resources have established TE Connectivity as a global leader in sensor innovation. We offer support and guidance from conceptual design to a final product.

Sun sensors are essential for spacecraft navigation systems. These unique navigational instruments detect the position of our Sun by using two axis data to orient a satellite. They help provide attitude control and orient the solar arrays for maximum power production. These small, lightweight devices can help detect faults and identify component failures by providing information on data discrepancies. They are crucial for calibration of onboard gyroscopes and help allow satellites to regain their bearings after a system malfunction.

• Fiber optic communication relies on photodiodes to convert light energy to electrical energy in proportion to the light intensity. This allows high speed data transmission over long distances.
  
• Free Space Optical Communication (FSOC) enables wireless, high-speed, secure, data transmission through free air, space or vacuum. Like fiber optics, modulated pulses of light are transmitted, carrying data to a receiver.

• Infrared thermometers detect infrared radiation emissions from an object, transforming them into an electrical signal that can be displayed as a temperature.
  
• Pulse oximetry uses photo-optic sensors mounted in a non-invasive probe, such as a clip or a band. Two LEDs with different light frequencies are passed through the patient’s tissues (fingertip, earlobe, or elsewhere) to determine the quantities of oxygenated and non-oxygenated blood. From these values, the probe can calculate the relative blood oxygen content. This method is used in medical facilities worldwide for safe, comfortable and effective monitoring of blood oxygenation.
• Smart textiles use integrated fiber optic sensors to measure strain or displacement. For example, instruments can monitor a patient’s breathing by measuring strain from these sensors. A computer interprets electrical signals, proportional to the frequency of expansion and contraction of the patient’s lungs, as their respiration rate. This technology is important for monitoring a patient’s vital signs during MRI procedures where electronic sensors cannot be used.

• Assembly lines incorporate optical sensors to verify position, dimension, composition and/or alignment of components. This is critical to the automation process since it facilitates assembly and inspection without requiring human intervention.
  
• Autocollimators are a critical part of the active alignment process which involves using optics to optimize component placement by measuring the angle or intensity of reflected light. This process helps improve product performance and reduce geometric accuracy requirements.
• Ellipsometry has become a key non-destructive and contactless optical technique for analyzing thin films. These layers of material range from fractions of a nanometer to several micrometers thick. They are used to enhance component properties of engine parts, semiconductors and even optical sensors themselves.

• Photovoltaic (PV) energy is collected using photodiodes, similar to those used in optical sensors, that directly convert light energy into electrical current. Each photodiode can generate 35 to 70 milliwatts on a clear sunny day. Solar cells composed of interconnected photodiodes can generate from 1 to 5 watts. These PV solar cells are then combined into networks and sold as modular solar panels which can be used individually or in PV solar arrays. Light Management for PV solar arrays can be achieved directly by using optical sun sensors to optimize the orientation of solar arrays. Optical sensors are also used to analyze the effectiveness of lenses and mirrors designed to concentrate sunlight, enhancing solar cell performance.
  
• Wind turbines utilize optical sensors to enhance their safety, performance and reliability. These low-cost devices monitor critical components, providing early warning about out-of-balance rotating parts as well as material wear and fatigue. This real-time monitoring promotes safety, helps prevent costly repairs and avoid catastrophic mechanical failures. Fiber-optic grating sensors measure strain, temperature and curvature of turbine blades for predictive maintenance and performance optimization.
• Bioenergy is the world’s third-largest renewable electricity source. It involves converting organic materials (biomass) into energy by combustion, bacterial decay or gasification. Optical sensors play a crucial role in monitoring bioenergy production including continuous monitoring, ease of use, design flexibility, reduced contamination risk and integration with smart processes.
• Carbon Capture, Use and Storage (CCUS) technology removes carbon from the exhaust streams of combustion systems and other industrial processes. Infrared absorption and laser-based sensors detect and quantify carbon dioxide (CO2) and carbon monoxide (CO) in waste streams upstream and downstream of the carbon capture systems. Optical sensors are also used to monitor atmospheric carbon and other pollutants, measuring the success of pollution abatement efforts.

• Drug discovery is a process used to expedite identification of new candidate medications. Optical biosensors can help in identifying targets for new drug discovery as well as analyzing biomolecular interactions in real time.
  
• Optical biosensors are used to detect contaminants in blood, tissue and medications. They are critical to the safety and efficacy of pharmaceuticals as well as spotting bacteria, tumor cells, biomarkers, drugs or other toxins in blood, tissue and medications.

• Dry fire laser training is a method of practicing shooting skills without using live ammunition. It involves the use of a laser training cartridge or dummy firearms that produce precise laser beams when the trigger is depressed. The laser beam hits the target, showing exactly where the shot would have landed. This provides a sustainable, cost-effective means to improve firearms skills, capturing data about the accuracy and precision of firearm users.
  
• Airborne law enforcement is a unique application of Electro-Optical and Infrared (EO/IR) systems which employ drones equipped with specialized sensors used to detect and identify targets. These systems enable the safety of bystanders and law enforcement while suspects are apprehended.
• Gunfire detection systems use acoustic and optical sensors to identify the source and location of gunfire. Optical sensors enable extremely fast response to firearm discharge events by detecting a muzzle flash and estimating its location. Some systems use infrared light to enhance optical sensor performance under low-light conditions. In certain cases, the sensors can provide speed and trajectory information about the projectile which can help to identify the type of weapon fired.
• Border surveillance systems employ optical sensors to detect motion and temperature variances indicating the presence of living organisms. Night vision systems allow these systems to work in low light. The Linear Ground Detection System (LGDS) uses a network of distributed sensors that are interconnected by fiberoptic cable to locate and classify activities such as people, vehicle movement and low flying aircraft. Digging, gunfire and other suspicious events can also be monitored and investigated.
• Naval warships use optical sensors to enhance the crew’s understanding of their environment, assess targets and enable the survival of the vessel. These optical sensors are critical for detecting threats and targets on the surface and in the air. Autonomous navigation systems, in which optical sensors are used to help avoid collisions and remain on course, are increasingly prevalent in naval warfare.