Photonics Dictionary: L

A tool used to determine the curvature of a lens surface in terms of dioptric power. See lens watch; spherometer.

An experimental research technique by which absorbed or unabsorbed radiation is analyzed in order to characterize and determine material properties, concentration as well as behavior under the...

A laser cavity, also known as an optical cavity or resonator, is a fundamental component of a laser system. It is a confined region or space where light undergoes multiple reflections, leading to the...

The laser damage threshold refers to the maximum level of laser intensity that a material can withstand without experiencing damage. It is a critical parameter in laser applications and is...

An instrument usually consisting of a very long interferometer, 3 to 800 m, and a laser light source for the study and measurement of strain, such as those formed by earth tides and gravitational...

A method of measuring microbending losses in optical fiber by sandwiching a length of fiber between two parallel plates, with 150-grit sandpaper on the bottom plate. Different weights are placed on...

A lateral shearing interferometer is an optical device used in interferometry to measure phase differences between two beams of light. Interferometry is a technique that combines and analyzes...

Lens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance, quality, and characteristics of lenses. These instruments are essential for...

A dial depth gauge graduated in diopters; a lens measure.

An ophthalmic instrument used to measure the magnitude and direction of the maximum and minimum powers of a spectacle lens, and mark the optical center of the lens by an ink dot. When the lens to be...

A lock-in amplifier is a specialized electronic instrument used to extract and measure small signals embedded in noise or interference. It is particularly useful in fields such as spectroscopy,...

A lumen is a unit of measurement used to quantify the amount of luminous flux, which is the perceived power of light. In other words, the lumen measures the total amount of visible light emitted by a...