Inverse length has the dimension inverse length. The SI composite unit of inverse length is the inverse meter.

Maple knows the units of inverse length listed in the following table.

An asterisk ( * ) indicates the default context, an at sign (@) indicates an abbreviation, and under the prefixes column, SI indicates that the unit takes all SI prefixes, IEC indicates that the unit takes IEC prefixes, and SI+ and SI- indicate that the unit takes only positive and negative SI prefixes, respectively.  Refer to a unit in the Units package by indexing the name or symbol with the context, for example, diopter[standard]; or, if the context is indicated as the default, by using only the unit name or symbol, for example, diopter.

The units of inverse length are defined as follows.

A diopter is defined as an inverse meter.

A kayser is defined as an inverse centimeter.