Currently, the mainstream distance measurement modules on the market are divided into three types: 905nm, 1064nm, and OPO 1570nm. There are significant differences among these three in terms of safety, distance measurement, and environmental adaptability.
The 905nm module has a low cost and mature silicon-based detector, but the laser in this wavelength band will directly reach the retina, which limits the safe power. It is severely interfered by stray light in strong light and rain/fog conditions, and the effective measurement range is mostly within several hundred meters, making it suitable only for short-distance indoor measurements.
The 1064nm module has better penetration than the 905nm module and is mostly used in surveying equipment. It also belongs to the dangerous wavelength band for the retina. High-power use poses safety risks, and its stability in sunlight environments is average. It performs poorly in long-distance scenarios.
The OPO architecture at 1570nm is the optimal solution among the three in terms of comprehensive performance. The laser at this wavelength is absorbed by the cornea and does not damage the retina. It allows for higher emission power and has been measured to achieve stable ranging up to tens of kilometers. The solar spectrum radiates weakly at this wavelength, and the echo signals in dusty and foggy environments are clear. Its anti-interference ability far exceeds the other two models. At the same time, the 1570nm laser has strong concealment and is not easily captured by electro-optical detection equipment, making it suitable for professional scenarios such as low-altitude security, border observation, and airborne long-distance detection.
For short-distance and low-cost applications, 905nm can be selected; for conventional topographic mapping, 1064nm can be chosen; for outdoor applications with ultra-long range, all-weather operation, and high safety requirements, the OPO 1570nm ranging module is the preferred option.