Photonics Dictionary

Operation in which the minimum detectable signal has its limits set by the thermal noise of the detector, the load resistance and the amplifier noise.

A technique for removing thermal noise and drift from focal plane assemblies by sampling the system output between views of scene elements and then subtracting the resulting value from the subsequent...

A cryogenically cooled long-wave infrared (LWIR) camera is a specialized thermal imaging device designed to detect infrared radiation in the long-wave infrared spectrum, typically ranging from 8 to...

Dark current density refers to the electric current that flows through a semiconductor device in the absence of any external illumination. It is primarily caused by thermal generation of charge...

A detector-Dewar assembly typically refers to a combination of a detector and a Dewar flask used in scientific instruments, particularly in the field of infrared spectroscopy or other applications...

An EMCCD (electron-multiplying charge-coupled device) camera is a type of scientific camera specifically designed for low-light imaging applications that require high sensitivity and fast readout...

FTIR (Fourier transform infrared) spectrometer is a powerful analytical instrument used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas sample. It operates based...

A heat sink for a laser is a device designed to absorb and dissipate the excess heat generated by the laser during operation. This is crucial to maintain the laser's performance, prevent overheating,...

An infrared detector is a device that is used to detect and measure infrared radiation, which lies beyond the visible spectrum of light. These detectors are utilized in various applications,...

A form of laser output noise that is caused by thermal, mechanical, or acoustical disturbances of the cavity length. Mode sweeping occurs when the length of the laser cavity changes as a result of...

Any noise or current fluctuation that prevents precise measurement of the signal current. Both dark current and signal current have random fluctuations that affect the arrival of pulses. Thermal...

In a thermal imaging system, the change in temperature that yields a signal-to-noise ratio of unity.

Noise equivalent thermal distance (NETD) is a performance metric used to quantify the sensitivity of thermal imaging systems, including photoacoustic imaging systems. It represents the smallest...

Optical artifacts refer to undesired or unintended effects that can occur in optical systems, such as microscopes, cameras, telescopes, and other optical instruments. These artifacts can distort or...

Optical noise refers to undesirable fluctuations or disturbances in an optical signal that can affect the quality or integrity of the transmitted information. This type of noise is particularly...

A read-out integrated circuit (ROIC) is an electronic device used in imaging systems, particularly in infrared (IR) and other sensing technologies. It is designed to interface with an array of...