Fenix LEP Torches - what are they?
Fenix is world renowned for manufacturing high-end professional LED personal lighting tools. These include small keychain torches right through to impressively powerful search lights. But Fenix also produces a torch type incorporating new laser technology.
The distance these lights reach is incredible, with the Fenix HT30R LEP (Light Excited Phosphor) torch driving a focused 500 lumen beam right out to 1500 metres.
Whilst yes, a Laser Torch, it doesn’t in fact shoot out a laser beam. Instead, it uses clever technology to generate a concentrated white light beam. Okay, its time to don your lab coats, lets get scientific.
LEP stands for Laser Excited Phosphor. Unlike an LED (Light Emitting Diode) where the light is generated from the LED itself, an LEP uses a powerful laser to generate an initial beam. Before we dive in I just want to remind you, white is not in itself a colour on the visible color spectrum, but is in fact a combination of all the visible colours. For instance, are you aware of the RGB colour system on your computer monitor or TV. This system uses Red, Green and Blue light to generate any colour on the visible spectrum, including white light.
Both LEP and LED lighting systems use phosphor, a material that emits light of an altered colour when exposed to light radiation. The phosphor changes the wavelength of the original light source to create the light colour that you see.
The white light output from a regular flashlight for example is created by a blue LED, emitting blue light that passes through the phosphor, producing some red and green light. This combines with the remaining blue light to create the white light that you see.
An LEP, in contrast uses a blue laser which is focused tightly by a lens onto a very small flouresent phosphor surface, backed by a metal substrate. The laser beam hits the phosphor and substrate, reflecting as a combination of blue light, combined with red and green light generated by the phoshor. These wavelengths combine to emit broad spectrum visible white light.
The white light generated is ‘Decollimated’ or defocused somewhat by the conversion process before being re focused into a useful beam through a series of optical lenses.
Whilst yes, you would have a somewhat more focused light there are limitations.
Fig 1.
When an LED generates photons, the light is spread out at a very wide angle. If we were to use the same focusing lens elements from and LEP, there would be a trade off due to the broad angle of light emitted by the LED source, with a lot of light emitted at wider angles not being collected and used.
Fig 2.
To collect more light you need a large lens very close to the LED. It is then difficult to focus the divergent light into a very tight beam pattern usable over long distance. The divergence of a light is how much it spreads out after being emitted from the torch.As you can see from above, LEP’s work so much better for long distance illumination in a compact flashlight as the light going into the system is already relatively well colliminated, so almost all the light will go through the lenses.
For LED’s a traditional reflector or newer TIR lens are the better options.
Here at Fenixlight UK we stock 2 LEPs. These are the TK30 and the HT30R.
TK30 is the original Laser torch launched by Fenix. Whilst part of the TK series it has a more slimline, sleeker looking appearance. This LEP torch features a rear activation switch and a side mode switch. The rear clicky switch design allows for the use of remote switches for weapon mounted for hunting purposes.
- The light has 2 outputs of Low and High.
- Low – 100 lumens | 600m distance | 6 hour runtime
- High – 500 lumens | 1200m distance | 3 hour runtime
For more information click here to go to our page on the Fenix TK30 Laser LEP torch
HT30R is the latest LEP torch from Fenix. Building on the success of the TK30, Fenix decided to add extra features. The biggest changes are the charge port and button operation. On the TK30, the torch is powered and recharged using a USB battery. The HT30R features on board charging with a USB-C port revealed when you rotate the head unit. The switching system now features dual switches in the tail cap, allowing you to switch on/off and change modes all with your thumb. Added to this, newer remote switches are now available, allowing for use of strobe mode.
- The light again features 2 outputs of Low and High.
- Low – 100 lumens | 600m distance | 7 hour - 15 mins runtime
- High – 500 lumens | 1500m distance | 2 hour - 20 mins runtime
For more information click here to go to our page on the Fenix HT30R Laser LEP torch
