what does fwhm mean in regards to an led optic output angle?

When we think about an LED optic we recall about a articulate plastic lens that is on top of the LED to focus or spread the lite. A lens for LED will function equally an optic to collect light and magnify its intensity towards the target.

Primary optics and secondary optics

A LED has a small protective dome over the diode, this is called the primary optic which serves both to protect and shape the output of the diode. However, the low-cal from the primary optic is notwithstanding too wide for most uses and it lacks intensity over distance. That is why most LEDs use a secondary optic as well, like reflectors and TIR optics. These secondary optics are besides used to collect calorie-free and magnify its intensity  towards the intended target.

Creating lenses for LED

Creating reflectors and lenses for LEDs (solid-land lighting) is unlike than just adjusting designs from other light sources. For instance, incandescent bulbs illuminate in 360 degrees, but LEDs are directional lighting, illuminating 180 degrees. The maximum bending LEDs can emit is 180 degrees as the substrate is on the back of the die.

Spatial distribution

Spatial distribution is used to draw the light coming from an LEDs primary optic. It refers to the shape, or spread, of the light from the eye of the LED. You tin imagine a line running straight down the center of the diode. Spatial distribution is measured in degrees from this centre point. The emitted calorie-free will be stronger in the centre. Forth the center the diode emits 100% of its relative luminous intensity and information technology will lose intensity farther away from the center. The use of a secondary lens or optic is needed to intensify the light and use the brightness and efficiency of the diode to total capacity.

Focusing lenses for LEDs

Loftier power LEDs give off a Lambertian light distribution. Significant that the brightness is the same for an observer, regardless of his or her position. Fifty-fifty when looking at the low-cal source from the far side it is noticeable that the low-cal source is extremely bright. This is where secondary eyes can assistance, they collimate the light into a controlled axle that will bring the intensity to the area where needed. Collimated lite rays volition spread in parallel (yet, information technology is incommunicable to brand the calorie-free exactly parallel considering of finite physical size of the emitter and diffraction).

Full width half maximum (FWHM)

FWHM is the angular width of the axle when the intensity at the edge is half the intensity in the center of the axle. This does non take into account the differences between optical platforms (due east.g. varying diode sizes), still it is a handy style to allocate optics. Fifty-fifty optics with identical viewing angles can differ in intensity and quality of the light axle, depending on the emitters optical design.

LED lens design and manufacturing

There are diverse factors to take into business relationship when designing an optic for your projection.

Axle Angle

The bending over which the emitted light is distributed. Lenses and reflectors are used to assistance create the desired beam bending. For example, narrow beam angles (due east.thou. 40°) accept a tight light beam and are commonly used for LED spotlights. Wide beam angles (e.g. 120°) have a big coverage for broad expanse lighting.

Improvidence

Clear lenses provide a well-baked axle of light. However, sometimes yous might want a softer border. Diffusion can assist offering a more compatible calorie-free output, especially when multiple LEDs are utilized.

Amount of LEDs per lens

Are you designing for a single LED or array? Multiple LED lenses are platonic for wide area lighting (east.g. street lighting).

Attaching

How volition the lens or reflector exist fastened? Will you lot twist or snap information technology onto a LED holder? Or will you use screws or special clips?

Custom lens for LED

Are you looking for a custom lens for your LEDs? Most of the bachelor stock optics for LEDs might non exist perfect for your project. And making changes to stock optics tin be costly and time consuming. However, with our unique solution you lot no longer accept to settle for sub-par optics. Addoptics offers smart manufacturing of polymer optics. Meaning you lot send u.s. your eyes design and nosotros manufacture a batch within a matter of days. Our unique approach is ideal for both prototyping also as series production.

Check our datasheet  for our most upward-to-date capabilities and material properties.

With our technology you lot can make employ of rapid prototyping for your optics project. For instance, you can send a couple of different optical designs. We can manufacture all of them, ship them to you within a couple of working days and yous can test and optimize the parts. Afterward testing and optimization nosotros can motility on to series production with the finalized blueprint.

If you would like to work with Addoptics and have your optics manufactured inside a couple of days, please feel free to reach out to us then we can hash out your projection.

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Source: https://www.addoptics.nl/optics-explained/lens-for-led/