Cutoff wavelength

In telecommunication, the term cutoff wavelength has the following meanings:

1. The wavelength corresponding to the cutoff frequency.

2. In an uncabled single-mode optical fiber, the wavelength greater than which a particular waveguide mode ceases to be a bound mode.

Note 1: The cutoff wavelength is usually taken to be the wavelength at which the normalized frequency is equal to 2.405. Note 2 : The cabled cutoff wavelength is usually considered to be a more functional parameter because it takes into consideration the effects of cabling the fiber.

Source: from Federal Standard 1037C and from MIL-STD-188