Plx logo

The Ultra Low-Profile RetroreflectorTM (ULPRTM) series is a cutting-edge ultralight compact retroreflector. This series truly represents the PLX brand by having a rugged stability, offered in a range of accuracy options and configurations. 



  • Superb optical stability over temperature, shock and vibration.
  • Single compact and robust unit.
  • Light-weight with protective aluminum housing.
  • Compatible with all major mounting systems.
  • Ideal for bore/collar mountings. 
  • Ideal for FTIR interferometer applications
  • Standard metallic coatings meet all applicable MIL specs, custom coatings available.
  • PLX is a registered ISO 9001 company.

Retroreflector Selector Chart

Coating Specification Chart


Hollow Retroreflectors

Ask a Question

The Ultra Low-Profile RetroreflectorTM (ULPRTM) series offer our lowest weight retroreflector option, with the rugged stability and accuracy that PLX is renowned for in the market. 

The Ultra Low-Profile Retroreflector™ (ULPR™) series will fit where other retros won’t. The ULPR™ is the ideal retroreflector series with a 36% weight reduction over the other retroreflector series. The round shape of the retroreflector is ideal for direct mounting on to bores, standard optical bench lenses and mirror holders. The newest member of the PLX retroreflector family pushes performance further with its compact and sleek patent pending mounting design. The Ultra Low-Profile Retroreflector™ is also extremely stable across varying temperatures, vibration levels, and shock conditions.

Optically, the ULPR™ performs the same as the rest of PLX’s retroreflectors, returning light parallel to its incoming direction. The hollow design, of three front surface mirrors, eliminates material absorption and chromatic aberration that plagues prism style retroreflectors.  The mirrors can be coated to maximize performance over a spectral range from the UV to the far IR.

The ULPR™ series is available in standard sizes of 0.5 in (12.7mm) to 5.0 in (125mm). The units are available in accuracies to 0.25 arc seconds beam deviation and λ/10 wave reflected wavefront error. The ULPR™ is provided in a versatile housing, which is compatible with all major mounting systems. The ULPR™ is available with a broad range of standard metallic coatings which meet all applicable MIL-specs. Unprotected metallic coatings are especially suited to interferometric applications. Custom coatings are available upon request.

Retroreflector Selector Chart

Specification Chart
Model Clear Aperture
Beam Deviation
ULPR-05 ULPR-05 0.5/12.7 3.0 - 15.0 0.30 - 0.90 3.26
ULPR-10 ULPR-10 1.0/25 1.0 - 30.0 0.15 - 3.50 17.4
ULPR-15 ULPR-15 1.5/38 0.5 - 30.0 0.10 - 5.25 46.6
ULPR-20 ULPR-20 2.0/51 0.5 - 30.0 0.15 - 7.00 96-105
ULPR-25 ULPR-25 2.5/63 0.5 - 30.0 0.25 - 9.00 159-168
ULPR-50 ULPR-50 5.0/127 0.5 - 30.0 0.45 - 18.0 840-980
Download our product datasheet