A lightweight mirror refers to a high-performance optical reflective component that significantly reduces its own mass by selecting specialized materials and adopting lightweight structural design, while maintaining or improving its optical performance, stiffness and stability.

I. Core Design Concept

The essence of lightweighting is to remove non-effective mass. Weight reduction is achieved on the non-optical surface (the back surface) through methods such as hollowing, drilling holes, and constructing support structures, while ensuring the precision and rigidity of the mirror surface (optical surface).

Weight reduction ratio: typically 50%–80% (compared with solid mirrors of the same aperture).

Core objectives: light weight, high stiffness, high thermal stability, and high precision.

II. Common Materials

Silicon Carbide (SiC)The preferred material. It features low density, high hardness, extremely low coefficient of thermal expansion, and excellent rigidity. Suitable for harsh environments such as space telescopes and high-power lasers.

Ultra-low Expansion Glass (Zerodur)Extremely high thermal stability and extremely high surface figure accuracy. Commonly used in ground-based astronomical telescopes.

Aluminum / Titanium AlloysLow density and easy to process. Aluminum mirrors have a high lightweight ratio (>60%), while titanium mirrors offer better strength and thermal stability.

Fused Silica / Synthetic QuartzGood optical homogeneity and moderate cost, mostly used for small and medium-aperture mirrors.

III. Key Advantages and Application Scenarios

Aerospace / Aviation: Significantly reduces the payload of satellites and spacecraft, saves launch costs, and serves as a core component for space telescopes and remote sensing satellites.

Astronomical Observation: Used as primary mirrors for large-aperture ground-based telescopes to reduce self-weight deformation and improve tracking mobility.

High-Power Lasers: Small thermal deformation ensures beam quality.

Portable Optical Equipment: Improves the portability of handheld / mobile system