LASER Grow lights

Dreddd

Well-Known Member
Hello everyone,
Laser grow lights have been on my mind for a while now, i always wondered if using Laser diodes would produce better results then LEDs at similar/lower wattage, since lasers produce coherent light while LEDs (and pretty much everything else) produces incoherent light, what the effect on plant growth might be...

recently i've found this study:
http://www.nature.com/articles/srep33885

that suggests that you can grow plants from seed to seed with a mix of red and blue laser diodes at a ratio of 9:1 of red (671 nm) : blue (473 nm), giving an average of total photon flux density of 90–100 μmol m−2 s−1
from a total wattage of 500mW.

in this experiment the beams were hitting a diffuser with a 50-degree divergence angle 20cm above the plants illuminating an area of 227 cm2.

they tested this laser illumination prototype on the Arabidopsis thaliana model plant and noted that the plants appeared to be healthy and were able to complete a full growth cycle from seed germination to the production of viable seeds.

srep33885-f4.jpeg

This seems interesting but i'm not sure how these findings stack up versus current LED technology (Cobs/QBs), what do you guys think?

EDIT: forgot to mention that in the comparison graph the "W" are the control plants grown with a florescent bulb also measuring a photon flux density of 90–100 μmol m−2 s−1 at the canopy.

cant say i understand this data 100% but even when i think about the most efficient LED diodes on the market today, i think Nichia has a 210lm/W diode running at 1w, would a single one of those LED diodes running at half strength be able to produce the same results?
 
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MeGaKiLlErMaN

Well-Known Member
We don't really use 1W diodes since they are not very efficient... Or 5W or even 10W we generally use COB based LED lights because they give the best lm/W for every price point. Unless these hit around 200lm/W or higher I don't see it being viable.
 

Dreddd

Well-Known Member
We don't really use 1W diodes since they are not very efficient... Or 5W or even 10W we generally use COB based LED lights because they give the best lm/W for every price point. Unless these hit around 200lm/W or higher I don't see it being viable.
That was true before quantum boards became a thing, dont get me wrong i use cobs myself and i love them, but you cant ignore the fact that individual diodes are more efficient.. the samsung LM561C diodes (less then 1w each) can get over 200lm/W and so can the top nichia diodes (although only in cool white), so if i take one of these highly efficient low watt diodes as a reference point for the lasers, at their peak efficiency, at 500mW they would produce 100 lumens, can you grow a plant from seed to harvest with just 100 lumens? seems like a stretch to me but i'm by no means an expert on the subject.
 

xX_BHMC_Xx

Well-Known Member
You would need a lot of lasers... the goal is to hit between 600-1000 ppfd for the average grower. How many diodes did they use for this test?
 

MeGaKiLlErMaN

Well-Known Member
That was true before quantum boards became a thing, dont get me wrong i use cobs myself and i love them, but you cant ignore the fact that individual diodes are more efficient.. the samsung LM561C diodes (less then 1w each) can get over 200lm/W and so can the top nichia diodes (although only in cool white), so if i take one of these highly efficient low watt diodes as a reference point for the lasers, at their peak efficiency, at 500mW they would produce 100 lumens, can you grow a plant from seed to harvest with just 100 lumens? seems like a stretch to me but i'm by no means an expert on the subject.
You can hit 200lm/W with cobs pretty easily. and still be around 25-50W each cob. Its still not cost effective as you're paying $75 per board and driving them at the same efficiency with the same amount of drivers. Instead of paying $30 a cob.
 

xX_BHMC_Xx

Well-Known Member
You can hit 200lm/W with cobs pretty easily. and still be around 25-50W each cob. Its still not cost effective as you're paying $75 per board and driving them at the same efficiency with the same amount of drivers. Instead of paying $30 a cob.
What COBs are you getting 200 lm/w out of?
 

Dreddd

Well-Known Member
You can hit 200lm/W with cobs pretty easily. and still be around 25-50W each cob. Its still not cost effective as you're paying $75 per board and driving them at the same efficiency with the same amount of drivers. Instead of paying $30 a cob.
Whatever, you're missing the point, this isnt a Quantum board vs Cob thread, its about whether a Laser diodes can grow plants more efficiently then LEDs can, i was using Quantum board LED diodes as an example of high efficiency but it really doesn't matter in what form factor the chip is, the fact is that they only used 0.5w to grow a plant to seed seems incredible to me since the most efficient LEDs on the market would only produce 100 lumens for the same wattage, and i have a hard time believing that would be enough, but i haven't crunched the numbers yet.

You would need a lot of lasers... the goal is to hit between 600-1000 ppfd for the average grower. How many diodes did they use for this test?
i'm not sure how many diodes since the light was built for them and they only state the wavelengths and wattage, but it technically shouldn't require that many diodes since they come in many intensities, 500mW is really common but there also 2W diodes out there, it isnt cheap though..
 

MeGaKiLlErMaN

Well-Known Member
What COBs are you getting 200 lm/w out of?
4000K 70 CREE CXB3590 @ 45W should get you there. But lumans dont matter anyways. Its been proven that 3500K 90 CRI is the best option for yield.

What Im running, did ok in flower. could be better.

CXB3590DB36V4000K 1 COBS @1.4A ON 1.813 PROFILE HEATSINK
1 SQ.FT. CANOPY 94% EFFICIENT DRIVER @15 CENTS PER KWH
Total power watts at the wall: 52.13
Cobs power watts: 49
Total voltage forward: 35
Total lumens: 9660
Total PAR watts assuming 10% loss: 27
Total PPF: 122.31
PPFD based on canopy area: 1316.53
PAR watts per sq.ft.: 27.0
Cob efficiency: 61.03%
Power watts per sq.ft.: 49.0
Voltage forward per cob: 34.89
Lumens per watt: 197.14
 

Dreddd

Well-Known Member
Well i crunched the numbers and if my calculations are right, according to the data provided in this experiment it would take:
80W of Laser light to provide 1000 PPFD for a 2x2 space and 320w for a 4x4.

This is assuming the plants have the same PPFD requirement from coherent light as they do with incoherent, who knows, they might need less light.
 

MeGaKiLlErMaN

Well-Known Member
Well i crunched the numbers and if my calculations are right, according to the data provided in this experiment it would take:
80W of Laser light to provide 1000 PPFD for a 2x2 space and 320w for a 4x4.

This is assuming the plants have the same PPFD requirement from coherent light as they do with incoherent, who knows, they might need less light.
In a 4x4 area you can make a light At 600wthat will push the same PPFD for about $1200 including everything. chillgrowLED is where, 2.69-2.97umole/W. If you can make better I would love to see it! Competition is what fuels innovation.
 

TogiX

Active Member
4000K 70 CREE CXB3590 @ 45W should get you there. But lumans dont matter anyways. Its been proven that 3500K 90 CRI is the best option for yield.
Lumens matter just as much as these calculators. CD bin is 52.5% efficient @ 23.5w via integrating sphere data, so I'm guessing DB bin is around 50-53% efficient @ 50w, right alongside CXM22 and Vero29C.

If QB numbers are correct then they've got COBs beat by a good margin.
 

MeGaKiLlErMaN

Well-Known Member
Lumens matter just as much as these calculators. CD bin is 52.5% efficient @ 23.5w via integrating sphere data, so I'm guessing DB bin is around 50-53% efficient @ 50w, right alongside CXM22 and Vero29C.

If QB numbers are correct then they've got COBs beat by a good margin.
Vero 29 c is 57%efficient at 50 w
 

TogiX

Active Member
Vero 29 c is 57%efficient at 50 w
I'll believe that when I see sphere data but from CD bin sphere numbers and CobKit's graphs I've determined that Vero29C is around 50% efficient at 50w. If you want 60% efficiency (or 11 PPFD/J @ 12") then you'll need to drive these chips at about 10-15w each.
 

MeGaKiLlErMaN

Well-Known Member
I'll believe that when I see sphere data but from CD bin sphere numbers and CobKit's graphs I've determined that Vero29C is around 50% efficient at 50w. If you want 60% efficiency (or 11 PPFD/J @ 12") then you'll need to drive these chips at about 10-15w each.
Sure man I'm sure that tasty LED and Timber lie. vero isn't binned.
 

Randomblame

Well-Known Member
Would like to see a blue 50w laser(or 10 with 5w for me) emmitting white light thru a phosphor layer like cobs does. I've read something somewhere, but don't slapp me guys, I don't remember where. But as far as I remember it make a lot of light and as we all know, plants love to get the full spectrum not only two wavelength.
 

TogiX

Active Member
Sure man I'm sure that tasty LED and Timber lie. vero isn't binned.
Looking at the 600w kit, they are all 100w each and 290PARw/600 making them 48.3% efficient.

Edit: That was the Vero29B, the C version is 48.75% efficient.

To make 56% efficiency there would have to be a 15-20% jump in efficacy and that doesn't happen when you reduce the current by 50%.
 
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