High-Power Laser Salvaged From Headlights

[DiodeGoneWild]’s latest video lives up to the name. He takes apart a laser headlight to recover a pretty powerful blue laser. You can see the video, below.

The headlights work with blue laser diodes that excite phosphor to produce white light. Removing the outside trappings revealed a three-pin laser diode (the case is the third pin). There’s also a substantial heatsink. Removing the diode from the assembly is difficult, but it is easy enough to leave it in the heatsink and use the existing connector.

Of course, the phosphor and a filter have to go. Some destructive work with a screwdriver and pliers broke out the optics from a diode he’d destroyed trying to remove it. Then he replaced the optics on the remaining diode with the modified housing.

With a low-current test, the diode didn’t lase but did act as a regular LED. More current did the trick, though. The laser without the optics made a line rather than a spot but still had enough power to melt some plastic and light matches. To get a parallel beam, the internal lens needs to move closer to the diode, and a drill bit allowed that to happen, which reduced the beam’s divergence quite a bit, but didn’t create the best result.

With the proliferation of cheap laser modules, it is really worth scrapping a headlight? Maybe. But it is an interesting look inside of a modern headlight, either way. We’ve peeked inside these headlights before. Maybe you can turn those old headlights into an oven.

55 thoughts on “High-Power Laser Salvaged From Headlights

  1. A typical halogen headlight bulb is about 55 or 60 Watts. Efficiency is around 3.5% so 2 Watts radiated. A pair of 1W near UV lasers plus phosphor should yield about the same power output. The phosphors are very efficient. A pair of lasers plus phosphors plus dichroic filter plus lenses plus heatsink and PC board and current regulator is going to cost a lot more than a halogen lamp which is maybe 5 dollars. I don’t see the advantage. And, the ‘laser’ headlights or HID are typically very blue which is the worst sensitivity and acuity for the human eye.

      1. It does, but the human eyes sensitivity to blue and “sharp white” means opposing drivers will see vehicles with such as owned by assholes, even with correct light pattern adjustment.
        It’s just harsh towards everyone else in traffic.

        It’s the same with “sharp” on/off LED indicators during the night, like getting visually stabbed in the eyes about 60 to 120 times a minute.
        Though that does make them more visible on bright summer days, so car manufacturers should really use the outside light sensor to modulate the blinkers accordingly.

        1. The sharp-‘off’ LEDs are also *less* easy to locate quickly: it’s lost in an eye saccade. The slow-fade of a tungsten filament is *much* easier to locate. Easy enough to fix in an LED: just modulate the PWM to mimic the fade of a filament, but no manufacturer seems to feel actual driving safety and reduction of operator fatigue is a useful feature.

          Speaking of PWM: why on earth do many manufacturers use such a low PWM frequency (like 100 Hz)? Tail.lights.constantly.flickering.drives.me.nuts. (Looking at you, Cadillac, especially)

          Jeez, is it too much trouble to run it at 40 kHz or something?

          1. The stroboscope effect makes the light appear brighter, but it only works if the on pulse is long enough for the eye to “saturate” to it. With higher PWM frequencies it starts to look dimmer.

          2. “stroboscope effect makes the light appear brighter,”[reference needed]

            Just to be clear: you’re saying a LED pulsed at (say) 20% duty appears brighter to the human eye when pulsed at (say) 120 Hz rather than (say) 10 kHz?

            Extraordinary claims require proof…

            (this *is* true at around 1-3 Hz, and conspicuity increases when the ‘on’ time is closer to 20-30% than 50%, for a given total energy. But at 120 Hz?)

          3. toyota and audi both have ‘reverse’ sequential led turn signals that will light up fully, and then fade away towards the direction of indication. unfortunately, they apply them inconsistently their lineups.

      2. Fluorescent paint doesn’t last long in sunshine applications – it has to absorb the UV energy and re-emit it; doing that causes damage to most pigments causing them to fade. Signs and markings usually depend on retro-reflective optical elements such as small spherical glass beads to be more readily visible.

        One thing blue light does is obliterate the visual purple adaptation to darkness meaning that off-axis views and oncoming drivers will be crippled, blinding everyone exposed to high levels of blue to areas that have lower levels of illumination. It’s why astronomers use red lighting to get by with.

    1. The advantage comes from the reduced need for your alternator to deliver the power to keep the bulbs lit. That energy has to come from somewhere, and that somewhere is from burning fuel. More efficient lighting = better MPG, plus they should last the life of the car thus need less maintenance.

      1. An accepted value is 33.7 kWh per gallon of gasoline. Reducing 60 W/bulb to 0 would save 1 gallon in 280 hours of operation, currently less than $5 in most of the US. A laser headlamp assembly is roughly $1000 each right now – so you need to operate the lamps for 280 hours * $2000/$5 to break even, or a bit over 100,000 hours. At 50 mph that’s going to be about 5 million miles of driving, which seems like a lot.

        1. That 33.7 kWh is the *thermal* energy content of gasoline. A little bit (well, a lot) disingenuous of the EPA to promote that, but that’s a different rant.

          By the time you go through the ICE conversion to mechanical energy, losses in the drive belt, the alternator, excitation current and the rectifiers, you get about 10% of that out in useful electrical energy.

          Still awful payback time, but not quite as bad as you say.

          1. OK so only 500,000 miles of driving at night? Well that means I was completely wrong and I feel so bad about it. You should write a paper detailing all the losses so they can post about it.

        2. I think that the idea is not to save money, but to save pollution/greenhouse gas emission. And if the saving of a single car is obviously unsignificant, it becomes significant when multiplied by millions of cars.

          1. The selling price of an object is an excellent surrogate for its carbon footprint: The price represents the cost (resources) to build it, the resources used by the buyer to make that money, and the resources used by the seller spending the profits.

            If you’re spending $1700 to replace a 55 watt halogen bulb with a 1 watt laser, it’s doubtful you’ll ever recover the resource cost footprint of the expensive light source, regardless of scaling to millions of cars.

          2. Solar panels, wind turbines, hybrid car, hydrogen fuel cell… All these technologies are much more expensive than burning coal or gasoline. So should we abandon them?
            Considering only cost/money to make choices is certainly not the best and cleverest way of thinking…

          3. @Gérald Electricity from solar is cheaper than from coal now. EVs are also now cheaper top operate considering fuel costs and maintenance than ICEs for the same class.

        3. I believe the reasoning is not just fuel efficiency from direct power savings but also improved safety due to better lighting, improved packaging (smaller lights / fitting in weird spaces), reliability, weight…

          Now, currently, it’s mostly luxury cars with LED or laser headlights the the units (list) price reflects that, but not so long ago the same was true of electric windows and air conditioning and now they’re standard fitment on vans.

    2. Parroting the marketing department here but one reason for having them is lighting up far away objects better. If you’re at motorway speeds you’re going to need 100+ metres to stop so your lights should cover that distance and more. To do that with halogen lights would be tricky, you’d need a lot of power and only a small fraction would reach that far, the majority would light your surroundings and make your eyes less sensitive.

      So how do you light far away objects without wasting light on nearby objects and without drawing kilowatts? Sharks with laser beams on their heads.

      1. As those far away objects are very often my eyes, I can perfectly live with the light profile and power we had the last century. Thank you very much. And I cannot phantom the idea that blinding the people around you is improving safety . Those lights work actually perfectly well on a flat, straight course. It’s a pity that there are curves and bumps in the real world.

        1. The idea is to apply light selectively unlike a 5kw halogen light. The lasers augment your existing headlights with an extremely-far-reaching point of light that is only enabled at high speed and with no other cars around. Meanwhile ‘digital headlights’ give you a kind of selective dipped mode by splitting your headlights into thousands of light sources all angled differently. When a car or person’s detected the light sources pointed at it can be dimmed while the rest of your beam remains full. Tesla Bjorn has some videos on it and it looks like there’s a black box painted over the car that follows it around bends, it’s pretty amazing.

          Not that I travel on unlit motorways but I can appreciate how cool the tech is while getting by with basic LEDs at low speeds on lit urban roads.

      2. Low beams can cast light 80 meters maximum by law in Europe. And high beams need to cast at least 100m by law. So going with new technology to get a better light beam in front of you is not needed because normal bulbs already do the job. Anything more would be illegal and a safety hazard for other drivers.

    3. If you have blue HID’s then you are doing it wrong. My HID’s are 4300K and don’t look blue at all. The higher the K the more blue/purple you get and all that does is cause eye strain and produce less visible light. Also wattage had nothing to do with brightness.

    4. Profit-center.

      You can get a replacement halogen headlamp for less than ten dollars.

      From his other videos these units are apparently Range Rover /Jaguar parts…one lens assembly lists north of US$1700 apiece, and they don’t appear to be serviceable. Guaranteed to last a month longer than the warranty.

      1. Yes, but I have to drive an awful lot of miles at night to realize any savings.
        The amount is miniscule compared to the amount used by drive motors, pumps and hvac.
        My volt for example uses 2.5 kw for the ac, and about 5 for heat.

        The drive motors depend on load, but vary from 5-100+ with lighter load once moving consuming less power

    5. It has some advantages, especially on automotive industry. Those laser headlights (Osram took the chance and trademarked the name for phosphor laser to “phaser”) have no moving parts and don’t age significantly in the livetime of a car.
      The problem with the unfitting light colour was addressed by microdotting the phosphor, so the emitted light is a mixture of original blue laser light & yellow phosphor light.

  2. Another advantage might be that, as with LED lights, you can generate various intensity profiles to vary the spatial illumination on the road. You just need two MEMS mirrors. Try this, or just changing the direction the headlight points to, with halogen bulbs.

      1. Until recently in the US the NTSB outlawed moving headlights or any movable or variable light shaping whatsoever except for high/low beams, and the shapes of the light output distribution of those are rigorously specified.
        It looks like they just last week have decided to maybe allow some adaptive headlight technologies.

          1. Motorbikes are allowed a lot of things that cars aren’t.
            Must have at least two but not more than four headlights.
            Must meet emissions standards (equals: must have a catalytic converter).
            Must have supplemental restraint systems (air bags).
            Can’t lane-split.

  3. What pisses me off is the driving lights below the headlights that here in Australia are not to be used driving around at night in traffic. Some are as strong as a headlight beam and hit you in the eyes.
    Also high bodied cars such as 4 wheel drives that I think should have their headlight adjusted down as to not shine in drivers eyes. It’s bad enough when they come up behind you and they shine in your mirrors.
    I drive a spinter van a pretty high vehicle but me lights done blind people

    1. Same problem here. I drive a chevy volt and it’s a bit lower than most cars.
      I have an auto dim rearview mirror that helps some , even more so since I turned it clockwise 45 degrees, pulled it away from the windshield and was able to continue on and end up with the mirror upside down ( this places the light sensor on the bottom of the mirror, which reacts sooner )
      Now if I could just set the side mirrors to reflect the lights into the drivers head area……

    2. I talked to an officer here about the problem and he said extra lights are considered ‘fog lights’ and can be on with low beams and there is no standard for brightness. So I asked him if I could use led aircraft landing lights as ‘fog lights’ and he paused, and said yes

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