Your Concave Mirror Questions, Answered (Automotive LiDAR)

For engineers working in Automotive LiDAR, the choice of a reflective surface is rarely an afterthought. Concave Mirror components sit at the heart of systems where…

For engineers working in Automotive LiDAR, the choice of a reflective surface is rarely an afterthought. Concave Mirror components sit at the heart of systems where measuring distance by timing reflected light pulses, and a small improvement in coating quality can change the result of an entire measurement or process.

Think of the Concave Mirror as a precisely made BK7 or fused silica plate whose working surface is a dielectric or metallic. The result is > 99% reflection across laser line or visible, which is exactly what most Automotive LiDAR builders are looking for.

When light meets the Concave Mirror, almost all of it bounces from the front coating. The substrate merely holds the coating in place; it does not need to be traversed by the useful beam, so transmission losses and secondary reflections stay minimal — a real advantage in sensitive Automotive LiDAR setups.

The dielectric or metallic is where performance is won or lost. Deposited by vacuum processes, it is tuned so the reflected wave adds constructively across laser line or visible, reaching > 99%. Getting the layer thickness right is a precision task: a few nanometers off and the reflectivity curve shifts.

Behind the coating sits the BK7 or fused silica substrate. Its job is mechanical: hold flatness, survive cutting and mounting, and stay stable with temperature. For many Automotive LiDAR uses, BK7 or fused silica hits the right balance of cost, flatness (λ/10) and workability.

Typical specs worth putting on a drawing: surface flatness λ/10, surface quality 20-10 (scratch-dig), substrate BK7 or fused silica, thickness 1–10 mm, and reflectivity > 99% over laser line or visible. Stating these up front saves rounds of sampling later. Our full technical specifications and standard sizes list the tolerances we hold routinely.

In Automotive LiDAR, the Concave Mirror usually appears wherever measuring distance by timing reflected light pulses. Designers value it because it keeps the beam path predictable and the loss budget small, which translates directly into a more stable instrument. The applications overview maps where each industry places it.

Frequently asked questions

Does a Concave Mirror need a specific mount angle? Not inherently, but 0° or 45° are most common; tell your supplier the angle so the coating is optimized. Can it be customized? Yes — size, shape, substrate (BK7 or fused silica) and dielectric or metallic are all adjustable. What reflectivity can I expect? Around > 99% across laser line or visible for standard builds.

A short checklist covers most Automotive LiDAR cases: what band (laser line or visible)? at what angle? how much loss is allowed (> 99%)? then pick dielectric or metallic on BK7 or fused silica at 1–10 mm. Getting these four right avoids the most common rework — the application notes show how each sector resolves them.

Mirrors reward careful handling. Hold a Concave Mirror by the edges, keep the coated face away from fingers and aerosols, and clean only with approved optics tissue and solvent when truly needed. Store it in its packaging, coated face protected, and it will hold > 99% for years.

At JYOPTO we make Concave Mirror parts by cutting BK7 or fused silica with laser accuracy of ±0.01 mm, then applying the dielectric or metallic under vacuum. Standard blanks run 1–10 mm thick, edges are smoothed for safe handling, and every shipped mirror meets λ/10 flatness with a 20-10 surface — the same disciplines we apply across our optical glass, vacuum-coating and precision cold-processing lines since 2020.

One term worth knowing

"Reflectivity" on a Concave Mirror is the fraction of incident light returned by the dielectric or metallic. Quoting > 99% without the band (laser line or visible) is meaningless, because the same coating can be excellent at one wavelength and poor at another — always pair the number with the range.

Beyond Automotive LiDAR, the same Concave Mirror shows up in laboratories, teaching setups and OEM builds where measuring distance by timing reflected light pulses. Its value is generality: one well-made part serves many breadboards, which is why stocking a few standard sizes pays off.

Environment matters. A Concave Mirror headed for Automotive LiDAR may see condensation, vibration and frequent handling. Specifying a sealed-edge, protected coating and a stable BK7 or fused silica substrate means the mirror keeps its figure (λ/10) and its reflectance through warranty periods and beyond.

Most Automotive LiDAR engineers reach for a Concave Mirror when they need measuring distance by timing reflected light pulses. The component's job is unglamorous but essential — keep the light on course and the loss low.

The dielectric or metallic is where performance is won or lost. Deposited by vacuum processes, it is tuned so the reflected wave adds constructively across laser line or visible, reaching > 99%. Getting the layer thickness right is a precision task: a few nanometers off and the reflectivity curve shifts.

Durability is part of the spec, not an afterthought. For Automotive LiDAR the Concave Mirror should survive shipping, installation and the occasional wipe. The protective overcoat on the dielectric or metallic is what lets it do that without losing > 99% over time.

A Concave Mirror is an optical component built so that reflection happens at the coated front face rather than through a substrate. With a dielectric or metallic on a BK7 or fused silica base, the part delivers > 99% reflectivity across laser line or visible while keeping the useful aperture clean and ghost-free.

A Concave Mirror starts as a BK7 or fused silica blank. We hold it to λ/10 flatness and 20-10 surface quality, then apply the dielectric or metallic. The substrate never sees the beam directly, but its figure sets the limit on how straight the reflected wavefront stays.

Most Automotive LiDAR engineers reach for a Concave Mirror when they need measuring distance by timing reflected light pulses. The component's job is unglamorous but essential — keep the light on course and the loss low.

Quality control

Every Concave Mirror is measured, not just sampled. Flatness against a reference, scratch-dig against 20-10, and a reflectance spot-check at laser line or visible confirm the dielectric or metallic performed as designed. Documented results matter most for Automotive LiDAR, where one bad part can stall a whole instrument.

The working principle is the law of reflection applied to a coated plane. Mount the Concave Mirror at 45° and a beam turns 90°; stack several and you fold a long path into a short box. That simplicity is why mirrors remain the fastest way to route light in Automotive LiDAR.

Optical designers sometimes treat mirrors as simple parts, yet in Automotive LiDAR the mirror decides beam direction, loss budget and even image contrast. The Concave Mirror is a quietly critical component whose details repay careful attention.

In short

For Automotive LiDAR, the Concave Mirror is less a commodity than a tuned component. Specify the band (laser line or visible), the reflectivity (> 99%) and the figure (λ/10), and you will spend less time debugging light you cannot see. That is the whole game. Where your application sits among the sectors we serve changes the details, not the method.