It has three mutually perpendicular surfaces and a hypotenuse face. Light entering through the hypotenuse is reflected by each of the three surfaces in turn and will emerge through the hypotenuse face parallel to the entering beam regardless of the orientation the incident beam. It is often used to the distance measurement, optical signal process and laser interferometer.
| Specifications | |
| Material | Optical glass |
| Dimension Tolerance | +/-0.05mm |
| Angle Tolerance | 30 arc second |
| Clear Aperture | >95% |
| Surface Figure | 1/4 wave @632.8nm |
| Surface Quality | 10-5 scratch and dig |
| Bevel | 0.1mmX45 degree |
| Coating | None, AR, AL... |
| Dia(mm) | Height(mm) | Coating | Item Number |
| 12.7 | 10.16 | none | ECC-001 |
| 12.7 | 10.16 | Silver | ECC-002 |
| 25.4 | 19.05 | None | ECC-003 |
| 25.4 | 19.05 | Silver | ECC-004 |
| 38.1 | 29.21 | None | ECC-005 |
| 38.1 | 29.21 | Silver | ECC-006 |
| 38.1 | 29.21 | None | ECC-007 |
| 38.1 | 29.21 | Silver | ECC-008 |
| 50.8 | 38.1 | None | ECC-009 |
| 50.8 | 38.1 | Silver | ECC-010 |
| 63.5 | 48.26 | None | ECC-011 |
