General Reference Articles

Photonics is the study of light and other types of radiant energy whose quantum unit is the photon. The impact of photonics on research, technology, navigation, culture, astronomy, forensics, and...

Prefixes for Binary Multiples The International Electrotechnical Commission (IEC) in 1998 approved as an IEC International Standard names and symbols for prefixes for binary multiples for use...

International System of Units (SI) SI Prefixes Multiples Factor Name Symbol 1024 yotta Y 1021 zetta Z 1018 exa E 1015 peta P 1012 tera T 109 ...

Table of the Greek alphabet and what the letters are commonly used to designate. Name Capital Small Commonly Used to Designate Alpha A α Angles, coefficients, attenuation constant,...

Physical Constants & Conversion Factors Length [I] 1 meter (m) = 39.3700 in. = 3.280833 ft = 1.093611 yd 1 kilometer (km) = 0.6213711 mi = 0.53996 nautical mi 1 micron (µm) =...

To order a copy of the latest printed version of the Photonics Spectrum Reference Chart, visit our bookstore at www.Photonics.com/wallchart.

Photometric Units SI Units Quantity Unit Luminous flux lumen lm Luminous intensity candela cd Luminance cd/m2 Illuminance lm/m2 lx Non-SI Units Luminous Intensity ...

Photonics Rules of Thumb Scientists and engineers tend to want to answer simple relational questions with a blackboard covered with equations, even when questioners just want a rough estimate to...

Density – % Transmission (Opacity x % Transmission = 100) Density Opacity %T 0 1.0 100 0.1 1.3 80 0.2 1.6 63 0.3 2.0 50 0.4 2.5 40 0.5 3.2 32 0.6 4.0 25 0.7 5.0 20 0.8 6.3 16 0.9 8.0 13...

A chart listing angle conversions – Degree, Minute, Second, Radian, Milliradian, Circumference and Quadrant Angle Conversions Angle Conversions degree min sec rad mrad circumference...

Material Coefficient of Expansion(×10-6 per °C) Density (lbs/cubic in.) Aluminum 23.8 0.10 Brass (cast) 18.8 0.30 Carbon (diamond) 1.2 0.25 Carbon (graphite) 7.9 - Copper 16.2 0.32...