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Telescope Optics Measurements


4D PhaseCam Twyman-Green interferometers are the industry standard for measuring concave primary and secondary mirrors. Vibration insensitivity enables measurements across long standoff distances without isolation.


The NanoCam HD measures roughness directly on the optic or on robotic positioners to ensure surface quality at every stage of polishing and coating.


PhaseCam systems can measure modal response to input signals and external vibration to verify control systems for adaptive optics. In the past, to measure the modal response of an adaptive optic to changes in the actuators, sensors have been used to measure movement at individual points on an optic—a slow, low-resolution solution. PhaseCams measure adaptive optics nearly instantaneously, as they actuate, verifying and calibrating the response of the actuators.

adaptive optic being measured as it is activated

Recording of adaptive optic, as it is actuated.



Added Technical Resources


Optical Metrology for Large Telescope Optics

Requirements for Meter-class metrology, large concave mirrors, and space structural support  hardware. Touching on Mirror Segment alignment, adaptive optics and aspheric optics.


Measuring Large Mirrors with Secondary and Tertiary Support Structures

An analysis system with an extensive tool set for measuring mirrors partially obscured by support structures.


Measuring Precision Telescope Optics (with a Streetcar Outside Your Door)

When Tucson’s Modern Streetcar was installed, NOAO’s Optics Shop turned to 4D’s Dynamic Interferometry to measure despite the vibration.

Products for Telescope Optics


Excels at fast, repeatable measurement of surface shape and transmitted wavefront error of flat and wedged optics. It is the most versatile Fizeau available, for any production environment.


4D PhaseCam Twyman-Green interferometers are the industry choice for measuring concave spherical optics, from several millimeters to tens of meters in diameter.

NanoCam HD

Surface Profilometer for measuring surface roughness on smooth and supersmooth surfaces. As a dynamic instrument, it can take measurements anywhere on a large optic without worrying about vibration. Highly portable, and pick-and-place automation compatible.

Do you need custom-built metrology?

Get a free consultation. 4D Technology’s mechanical, optical, electrical and software engineering teams are standing by to evaluate what it would take to meet your application’s requirements.

Get In Touch

(520) 294-5600


3280 E Hemisphere Loop, Ste 146
Tucson, AZ 85706


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Wed: 8am - 5pm
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