ERDI LASER
1535nm Eye-Safe Laser Source for LiDAR, 10uJ to 10mJ
1535nm eye-safe laser sources for LiDAR: 10uJ to 10mJ, up to 100Hz, narrow divergence, with UAV and airborne integration notes and datasheets.
Two LiDAR problems that need different lasers
LiDAR is not one requirement. A scanning system that builds a point cloud needs thousands of pulses per second at modest energy; a long-range system that measures one return through haze needs a few pulses per second at millijoule energy. Both are 1535 nm work, and they sit at opposite ends of the same model range.
Choosing between them is mostly a matter of deciding which quantity the system is short of: points per second or energy per point. The product of the two is limited by the average power the package can dissipate, and the model range is arranged along exactly that trade.
Scanning and mapping: the kHz end
These four models share a 6 g package, a 2 V / 5 A drive and a 4–5 ns pulse. They differ only in where they sit on the energy–rate curve, and the curve is close to constant average power:
| Model | Pulse energy | Repetition rate | Average power | Pulse width | Divergence |
|---|---|---|---|---|---|
| ER10 | ≥10 µJ | 5 kHz | 50 mW | 5 ns | <15 mrad |
| ER20 | ≥20 µJ | 2.5 kHz | 50 mW | 5 ns | <15 mrad |
| ER40 | ≥40 µJ | 1 kHz | 40 mW | 4 ns | <15 mrad |
| ER70 | ≥70 µJ | 500 Hz | 35 mW | 4 ns | <15 mrad |
Average power is the product of the first two columns, calculated from the published minimums. It stays within 35–50 mW across the four models, which is the design intent: the thermal budget of the package is what limits the pair, and the four points let a system designer place the energy where the link budget needs it without changing the heat path.
For a scanner the choice is usually made by the detector and the optics rather than by the laser. A small receive aperture and a fast, low-noise detector favour 40–70 µJ at 500 Hz–1 kHz; a system that can average many returns per voxel favours 10–20 µJ at 2.5–5 kHz. The high repetition rate page covers the trigger and thermal side of these models in more detail.
Long range and uncooperative targets: the millijoule end
When the return comes from a diffuse surface at a distance, the energy per pulse is the only lever that closes the link. At 1–10 Hz the thermal budget is no longer the constraint, so the package grows and the energy rises by two orders of magnitude:
| Model | Pulse energy | Repetition rate | Pulse width | Weight | Supply / peak current |
|---|---|---|---|---|---|
| ER400 | ≥400 µJ | 1–10 Hz | 6 ns | 12 g | 2 V / 15 A |
| ER8000 | ≥8 mJ | 1–5 Hz | 13 ns | 220 g | ≤14 V / 100 A |
| ER10000 | ≥10 mJ | 1–5 Hz | 12 ns | 220 g | ≤14 V / 100 A |
The step from ER400 to ER8000 is not a linear purchase: it is a different power supply (2 V to 14 V), a different current (15 A to 100 A) and a package that goes from 12 g to 220 g. Systems that end up at the top of the range are usually designed around the transmitter from the start, not adapted to it later.
1535 nm as a LiDAR wavelength
Most short-range LiDAR is built at 905 nm because silicon detectors are inexpensive and sensitive there. The 1.5 µm band changes the trade in two ways that matter for airborne and fielded systems:
- Eye safety — the pulse is absorbed by the cornea before it reaches the retina, so far more energy can be emitted where people or aircraft may be present. This is what makes long-range measurement in open environments practical at all.
- Detector choice — 1535 nm needs InGaAs or similarly extended-range detectors rather than silicon, which changes the receiver design and its noise budget.
The wavelength also sits outside the strong silicon-band solar background, which helps in daylight. It does not remove atmospheric loss: water-vapour absorption lines lie in this band and the operating wavelength has to avoid them, which is one reason the emission is specified at 1535 nm rather than "anywhere near 1.5 µm".
What the pulse width does to the measurement
Pulse width sets the range resolution floor and the detector bandwidth together. A 4 ns pulse occupies about 1.2 m of path, which corresponds to a single-shot resolution floor near 0.6 m once the return trip is accounted for; a 13 ns pulse is about 3.9 m of path, or roughly 2 m of resolution. A system that quotes centimetre resolution is not limited by the laser pulse but by its timing electronics — the pulse only has to be short enough not to dominate the error budget.
The other end of the same number is peak power: 10 mJ in 12 ns is a very different optical load on the receiver than 10 mJ spread over 100 ns. Both the detector's recovery time and the risk of saturating the front end from a close, bright return depend on it.
Airborne and fielded systems
Weight, supply and vibration screening dominate once the platform moves. The kHz models are 6 g on a 2 V rail; the millijoule transmitters are 105–220 g on 5–14 V at 80–100 A. The airborne and UAV page covers the mechanical and thermal side of integrating a 1535 nm source into a gimbal or a pod, and the package dimensions page gives the outline and mounting constraints per model.
Narrowing it down
Three numbers decide the model: required points per second, energy per point the link budget needs, and the supply available on the platform. Send those with the receiver type and the target description; the RFQ guide lists the rest.
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