mirror Comparison Table

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mirror comparison table

Subject has definition

active optics Controlling the shape of a telescope mirror at a relatively slow rate.

adaptive optics Compensating for atmospheric distortions in a wavefront by high-speed changes in the shape of a small, thin mirror.

Borosilicate

Cer-Vit

deformable mirror A very thin mirror whose shape can be changed by the force applied by many small pistons behind the mirror.

Fused-quartz

honeycomb mirror A construction method for a large mirror in which the back is hollowed-out to leave a ribbed structure that resembles a honeycomb.

meniscus mirror A very thin mirror with a high curvature. A method of constructing very large mirrors which assumes from the outset that the mirror is too thin to hold its shape against gravity and will require an active control system.

primary mirror The first mirror encountered by incident light in a telescope system.

Pyrex

secondary mirror The second reflecting surface encountered by the light in a telescope. The secondary is usually suspended in the beam and therefore obstructs part of the primary.

segmented mirror A large mirror construction technique in which many smaller elements are built and then actively controlled to conform to the shape of the required large mirror.

tertiary mirror The third mirror to be encountered by the light in a telescope system. A tertiary mirror is required on alt-az telescopes to direct light to the stationary Nasmyth foci.

Zerodur

Subject	has definition
active optics	Controlling the shape of a telescope mirror at a relatively slow rate.
adaptive optics	Compensating for atmospheric distortions in a wavefront by high-speed changes in the shape of a small, thin mirror.
Borosilicate
Cer-Vit
deformable mirror	A very thin mirror whose shape can be changed by the force applied by many small pistons behind the mirror.
Fused-quartz
honeycomb mirror	A construction method for a large mirror in which the back is hollowed-out to leave a ribbed structure that resembles a honeycomb.
meniscus mirror	A very thin mirror with a high curvature. A method of constructing very large mirrors which assumes from the outset that the mirror is too thin to hold its shape against gravity and will require an active control system.
primary mirror	The first mirror encountered by incident light in a telescope system.
Pyrex
secondary mirror	The second reflecting surface encountered by the light in a telescope. The secondary is usually suspended in the beam and therefore obstructs part of the primary.
segmented mirror	A large mirror construction technique in which many smaller elements are built and then actively controlled to conform to the shape of the required large mirror.
tertiary mirror	The third mirror to be encountered by the light in a telescope system. A tertiary mirror is required on alt-az telescopes to direct light to the stationary Nasmyth foci.
Zerodur

Next wavefront modifier: Nicol prism Up: wavefront modifier Previous wavefront modifier: lens