LED Light Guides are ideal tools if you need to efficiently link the output of a distant light source to the point of application. Such setups may be favorable out of various considerations. The need for a powerful light source combined with tight design envelope restrictions is one of the main motivations for implementing a light guide solution. Light-guide-coupled installations also have a clear advantage if you need high radiation output from a freely movable light exit, lightweight design, or need to fulfill strict safety requirements in a controlled environment. In any case, a light guide should have excellent transmission and show good mechanical flexibility and robustness while performing reliably over its long service life – Primelite’s LED Light Guides tick all these boxes.
LEDs are high-NA light emitters (broad angular radiation pattern). In an efficient setup combining LEDs and light guides, these light guides should be capable of transmitting as much radiation as possible to the point of application. In other words, the LED source’s NA must match the NA of the light guide. We offer single- and multi-pole liquid light guides, which perfectly fit our LED light sources. Typically, their power delivery is superior to conventional silica fiber light guides by a factor of two to three in our exposure systems.
Our Advanced LED Light Engines ALE/1 and ALE/3 use high-transmission LED Light Guides to flexibly deliver the optical system output right at the spot of application. Perfectly matching numerical apertures make the combination of our LED light sources and light guides a very efficient overall setup. Besides being very flexible and featuring excellent transmission, our standard LED Light Guides are highly customizable, can be either single- or multi-pole, and in some applications, their length extends up to 20 meters.
Primelite’s LED Light Guides design allows for continuous throughput of up to 50 Watts of incoherent radiation. Active cores optimized for the near ultraviolet (NUV), visible (VIS), and near infrared (NIR) spectral ranges are available and come in four different cross-sections. Following your requirements regarding the mechanical setup and transmitted power, the diameter of our LED Light Guides can vary between Ø3.0 and Ø8.0 mm.
You can expect a service life of multiple years if you use our LED Light Guides with our fiber-coupled LED light sources. Because of efficient light coupling, there is almost no excess radiation at the light entrance of the light guide creating undesirable heat and provoking premature failures.
It could be worth checking out our LED Performance Optics in many cases, too. As the numerical output aperture from our LED light guides is around 0.6 (2α ~70°), our lens systems can be an economical addition to reduce divergence or even focus radiation for maximum intensity. Our LED Performance Optics are also beneficial if you want to improve the uniformity of the exposure field, which can be either hexagonal or square in shape.
Primelite’s LED Performance Optics exclusively use UV-grade material.
The most outstanding feature of our LED Light Guides is the extreme acceptance angle (NA) for incoming radiation from the light source. Fused silica fiber light guides typically have a NA of 0.3, translating into angles of no more than α ±17.5° for the light they can transmit. Every ray coming in with a higher divergence will be rejected and absorbed at the fiber’s light entrance. Have you ever wondered why silica fiber light guides are advertised as being particularly heat resistant? It is because the rejected radiation creates unwanted heat – or in other words: fiber light guides are inefficient. Primelite’s LED Light Guides accept and transmit light with angles of up to ±35° resulting in power delivery that exceeds the capabilities of conventional fiber light guides by a factor of two to three.
It is not only the high NA that makes our LED Light Guides perform way better than comparable solutions. Excellent transmission in dedicated spectral ranges is also essential, peaking at 85% for our most popular NUV active core option.
Test conditions: radiation NA 0.6, light guide length 1.5 m, active core Ø6.5 mm