Photosensitive and other uses

Solite offers an extensive range of coloured LEDs, with many of our board designs crafted in-house, catering to various applications. In professional settings, coloured LEDs are often referred to as "narrow spectrum" LEDs. This term is used because these LEDs are engineered to emit light within very specific nanometre ranges, which enhances technical performance and visual acuity. Narrow spectrum LEDs are commonly utilised in the manufacturing of electrical components, such as semiconductor or silicon wafers, as well as in healthcare and cleanroom applications.

The graph below demonstrates the individual colours and the nanometre banding that is specific to them.

Solite provides several narrow spectrum options, including Amber, Green and Red, as well and dual colour options.

Photosensitive

Amber light sources are widely used as an efficient solution for blocking UV and blue light energy up to 500 nm. But why is this important?

When you look at the light spectrum, you'll notice that ultraviolet (UV) light sits just before the visible range. Although invisible to the human eye, UV light can be harmful in certain applications. For instance, during silicon wafer fabrication, exposure to UV light can damage the product. Therefore, it’s essential to eliminate UV light from the luminaire being used.

Solite achieves this by utilising LED chips that have minimal output below 500 nm, effectively reducing UV exposure.

As we know, UV light is present in the following ranges:

• UVA (Long-Wave UV): 320–400 nm
• UVB (Medium-Wave UV): 280–320 nm
• UVC (Short-Wave UV): 100–280 nm

As illustrated in the graph below, the peak output of the LEDs then moves into the yellow/amber range, resulting in a light source that appears amber. However, it's important to note that this shift does not negatively impact the luminaire's lumen output or efficiency

Visual acuity

Green illuminance is often used for tasks where visual acuity is important, this is because:

Peak Sensitivity of the Human Eye: The human eye is most sensitive to light in the green spectrum, around 555 nanometres. This sensitivity means that green light is perceived more vividly and clearly than other colours, allowing for better visual sharpness and detail recognition.

Enhanced Contrast: Green light provides excellent contrast against red and blue, the other primary colours of light. This contrast is beneficial for distinguishing different objects and details, which is crucial for tasks requiring precision and fine motor skills, such as surgery or laboratory work.

Reduction in Chromatic Aberration: Chromatic aberration is a type of distortion that occurs because different colours (wavelengths) of light refract differently as they pass through lenses. Since green light is near the middle of the visible spectrum, it experiences less chromatic aberration compared to the extremes of the spectrum (red and blue). This means images appear sharper and clearer under green light, enhancing visual acuity.

Minimisation of Glare and Eye Strain: Green light is less intense and less likely to cause glare compared to blue or white light, which can be harsh on the eyes, especially in prolonged use. Reduced glare leads to less eye strain, allowing for better sustained visual acuity over time.

Optimal Pupil Response: Green light helps maintain a moderate level of pupil constriction, balancing the amount of light entering the eye. This optimal level of constriction helps enhance focus and clarity, leading to improved visual acuity.

The 5 main benefits of green light are :

1. Reduced Eye Strain: Green light is easier on the eyes compared to other colours, especially in low-light conditions. In environments like operating theatres where surgeons and medical staff need to focus for long periods, green light can help reduce eye fatigue and strain.
2. Contrast Enhancement: Green light enhances contrast and visibility of details, which is crucial during delicate procedures where precision is paramount. This is particularly beneficial in surgeries where the differentiation of tissues and organs is essential.
3. Photostimulation: Green light has been shown to have a positive effect on alertness and concentration. In medical settings, maintaining focus and cognitive function is crucial, and green light can help in keeping medical personnel alert and attentive.
4. Colour Perception: The human eye is most sensitive to green light, which means it can help in distinguishing subtle colour variations and changes in tissues or fluids during medical procedures.
5. Sterility and Safety: Green light is often used because it does not interfere with certain sensitive equipment or chemical reactions in laboratories. It can also help maintain a sterile environment as it does not attract insects or disrupt sterile conditions like some other light colours might.

Animal Research

Red light sources are often used to provide comfortable night time lighting, without disturbing the circadian rhythm of animals within research environments.

A number of animals used within laboratory environments will have a visual spectrum from around 300-575nm. Red peak output sits around 630nm and offers undiscernible output of 570nm or below, this range sits comfortably within the human visible spectrum of 400-750nm allowing lab operatives to monitor the welfare of the animals, without disturbing their sleep patterns (Circadian Rhythm).

Solite can offer Red alongside white light in a dual circuit luminaire for daytime and night time use, or full circadian or colour tuneable lighting alongside a red circuit for full daytime simulation depending welfare needs of the animals concerned.