Technical Terminology

Comprehensive definitions of optical, infrared, and laser technology terms used in our solutions and products

Understanding Optical Technology

This glossary provides clear definitions of technical terms commonly used in our optical solutions, infrared systems, and laser products. Understanding these terms will help you make informed decisions about our products and their applications.

Focal Length

The distance between the lens and the image sensor when the subject is in focus. Measured in millimeters (mm), it determines the field of view and magnification of the lens.

F/# (F-Number)

The ratio of the lens's focal length to the diameter of the entrance pupil. Lower F/# values indicate larger apertures and better light-gathering capability, especially important for infrared imaging.

Field of View (FOV)

The angular extent of the observable world that is visible through the optical system. Usually expressed in degrees, it determines how much of the scene can be captured.

Magnification

The ratio of the apparent size of an object when viewed through the optical system to its actual size. Higher magnification provides more detail but reduces field of view.

Exit Pupil

The diameter of the light beam that exits the eyepiece and enters the observer's eye. Larger exit pupils provide brighter images and are easier to use, especially in low-light conditions.

Exit Pupil Distance

The distance from the last surface of the eyepiece to the exit pupil. Important for comfortable viewing, especially when wearing glasses or protective equipment.

Distortion

An optical aberration that causes straight lines to appear curved. Measured as a percentage, lower distortion values indicate better image quality and more accurate representation.

Transmittance

The percentage of light that passes through the optical system without being absorbed or reflected. Higher transmittance values indicate better light efficiency.

Numerical Aperture (NA)

A measure of the light-gathering ability of an optical system. Higher NA values indicate better resolution and light collection, particularly important for machine vision applications.

Zoom Ratio

The ratio between the maximum and minimum focal lengths of a zoom lens. A 10x zoom means the maximum focal length is 10 times the minimum focal length.

Thermal Imaging

Technology that captures and creates images based on the infrared radiation (heat) emitted by objects, rather than visible light. Used for night vision, surveillance, and temperature measurement.

Cooled Detector

An infrared detector that operates at cryogenic temperatures (typically -200°C) to reduce thermal noise and improve sensitivity. Provides superior image quality but requires more power and cooling systems.

Uncooled Detector

An infrared detector that operates at room temperature without active cooling. More compact and energy-efficient than cooled detectors but with slightly lower sensitivity.

NETD (Noise Equivalent Temperature Difference)

A measure of thermal sensitivity, representing the smallest temperature difference that can be detected. Lower NETD values indicate better thermal sensitivity, measured in millikelvins (mK).

MWIR (Mid-Wave Infrared)

Infrared radiation in the 3-5 micrometer wavelength range. Provides good thermal contrast and is commonly used in military and surveillance applications.

LWIR (Long-Wave Infrared)

Infrared radiation in the 8-14 micrometer wavelength range. Most commonly used for thermal imaging as it corresponds to the peak emission of objects at room temperature.

Focal Plane Array (FPA)

An image sensor consisting of an array of light-sensing pixels at the focal plane of a lens. The resolution is specified as the number of pixels (e.g., 640×512).

Pixel Size

The physical dimensions of individual detector pixels, measured in micrometers (μm). Smaller pixels can provide higher resolution but may have reduced sensitivity.

Non-Uniformity Correction (NUC)

A process that compensates for variations in pixel response across the detector array to ensure uniform image quality across the entire field of view.

Black-Hot / White-Hot

Display modes for thermal images where hot objects appear either black (black-hot) or white (white-hot) against the background. The choice depends on user preference and application.

Pseudocolor

Color mapping applied to thermal images to enhance contrast and make temperature differences more visually apparent. Various color palettes are available for different applications.

MRTD (Minimum Resolvable Temperature Difference)

The smallest temperature difference that can be resolved in a thermal image, typically measured in millikelvins (mK). Lower values indicate better thermal resolution.

Laser Wavelength

The specific wavelength of light emitted by a laser, measured in nanometers (nm). Different wavelengths are used for different applications (e.g., 1064nm for industrial, 1550nm for telecommunications).

Beam Expansion

The process of increasing the diameter of a laser beam while maintaining its collimation. Used to reduce beam divergence and improve focusing characteristics.

Beam Collimation

The process of making laser light rays parallel to minimize beam divergence over distance. Essential for long-range laser applications and precise targeting.

Laser Damage Threshold

The maximum laser power density that an optical component can withstand without damage, measured in watts per square centimeter (W/cm²) or megawatts per square centimeter (MW/cm²).

Spot Size

The diameter of the focused laser beam at the target. Smaller spot sizes provide higher power density and more precise material processing or measurement.

Scanning Angle

The maximum angular range over which a laser beam can be deflected for scanning applications, typically measured in degrees from the center position.

Working Distance

The distance from the optical system to the target where optimal performance is achieved. Important for laser processing and measurement applications.

Detection Range

The maximum distance at which a target can be detected by a thermal imaging system. Typically specified for human-sized targets under standard atmospheric conditions.

Recognition Range

The maximum distance at which a target can be recognized (identified as a specific type of object) by a thermal imaging system. Always shorter than detection range.

Ballistic Calculation

Advanced targeting system that calculates bullet trajectory, accounting for distance, wind, temperature, and other environmental factors to improve accuracy.

Fog Penetration

The ability of thermal imaging systems to see through fog, smoke, and other atmospheric obscurants that block visible light. Infrared radiation penetrates these conditions better than visible light.

Multi-spectral Imaging

Technology that combines multiple imaging channels (visible, near-infrared, thermal) to provide comprehensive situational awareness and enhanced target identification.

Target Positioning

GPS-based system that provides precise location coordinates of observed targets, often integrated with mapping and navigation systems for tactical applications.

Integration Time

The duration for which the detector collects light before reading out the signal. Longer integration times can improve sensitivity but may cause motion blur in moving targets.

Frame Rate

The number of complete images captured per second, measured in Hertz (Hz). Higher frame rates provide smoother video but require more processing power and bandwidth.

MTBF (Mean Time Between Failures)

A reliability metric indicating the average time between system failures, measured in hours. Higher MTBF values indicate more reliable equipment.

Operating Temperature Range

The range of ambient temperatures within which the equipment can operate reliably. Critical for outdoor and military applications where extreme temperatures are encountered.

Power Consumption

The amount of electrical power required to operate the system, measured in watts (W). Important for battery life and thermal management in portable systems.

Start-up Time

The time required for the system to reach full operational capability after power-on. Cooled systems typically require longer start-up times due to cooling requirements.

Optical Axis Stability

The ability of the optical system to maintain consistent pointing direction under various conditions. Measured in pixels, lower values indicate better stability.

Digital Zoom

Electronic magnification of the image after capture, as opposed to optical zoom which uses lens elements. Digital zoom can reduce image quality but provides additional magnification capability.

Reticle

Crosshairs or targeting marks overlaid on the image to assist with aiming and measurement. Can be adjusted for position and may include range-finding capabilities.

Video Output

The format and interface used to output video signals from the imaging system. Common formats include PAL, NTSC, CameraLink, and digital interfaces like HDMI or network protocols.

Communication Protocol

The method used for data communication between the imaging system and external devices. Common protocols include RS232, RS422, Ethernet, and various digital interfaces.

Bad Pixel Correction

Automatic detection and correction of defective pixels in the detector array to maintain image quality. Essential for professional imaging applications.

Image Enhancement

Digital processing techniques applied to improve image quality, including contrast enhancement, noise reduction, edge sharpening, and other algorithms to optimize visual clarity.

DDE (Digital Detail Enhancement)

Advanced image processing algorithm that enhances fine details and improves contrast in thermal images, making targets more visible and recognizable.

Sky-Ground Mode

Special imaging mode optimized for scenarios where targets appear against sky backgrounds, automatically adjusting contrast and brightness for optimal target visibility.

Strong Light Protection

Feature that protects the imaging system from damage when exposed to bright light sources, such as the sun or laser pointers, by automatically reducing sensitivity or activating protective filters.