We seem to have had a bit of a surge in demand for diagonal, or elliptical flat mirrors recently. We have just made some diagonal mirrors from gold coated copper with a diagonal angle of 60 degrees. When viewed at 60 degrees they have a circular profile. We have also made similar all metal mirrors from Stainless Steel for Laser Induced Breakdown Spectroscopy. Stainless Steel is generally used uncoated. Last, but not least as it is a great application for our laser mirrors, some small gold coated copper mirrors for Er:YAG surgical laser handpieces.
With surgical lasers, left-handed surgeons can have great difficulty using surgical equipment designed for right-handed surgeons, or when being trained by right-handed instructors. With lasers at least, it’s possible to use a mirror to “flip” the beam paths and allow right handed and left handed use.
The first diagonal metal mirror was probably made by Isaac Newton in 1668, juts a few miles from our factory here near Cambridge. It was the secondary mirror in the worlds first telescope to use reflective optics.