Optical Telescope Element (OTE)

The OTIS out of cryovac chamber at NASA Johnson.

The Webb Observatory is the space-based portion of the James Webb Space Telescope system. It is comprised of the Optical Telescope Element (OTE), the Integrated Science Instrument Module (ISIM), the sunshield and the spacecraft bus.

The Optical Telescope Element (OTE) is the eye of the James Webb Space Telescope Observatory. The OTE gathers the light coming from space and provides it to the science instruments. The OTE consists of the mirrors as well as structures and subsystems that support the optics.

2 3d rendering views of the Webb space telescope from the rear quarter and from below front quarter labelling with the major components.
Webb Observatory major components.
NASA/GSFC CIL
The OTIS out of cryovac chamber at NASA Johnson.
The OTIS (OTE+ISIM) out of cryovac chamber at NASA Johnson. The OTIS is an acronym that includes the OTE plus the Integrated Science Instrument (ISIM) package - essentially the optics and science instruments.
NASA/Chris Gunn

The OTE Consists Of:

OTE engineering diagram
OTE Engineering Diagram