New Frontiers in Solid State Lighting

OSRAM LED in a range of nature based applications

Aquarium LEDsLEDs have found their way into many general illumination applications and monochromatic LEDs have been used in various applications such as backlighting, automotive illumination, architectural, theatrical, and signage lighting. LEDs are also being used in a whole range of applications that can enhance the life of different species.

Plant Growth

Plants use light as a source of energy. Different wavelengths (peak wavelengths of 450nm, 465nm, 590nm, 625nm, 634nm, and 660nm) in the spectrum of light influence various aspects of plant growth. The cultivation of plants in a greenhouse environment, supported by artificial light, helps control all the elements that can influence the growth of the plant. Monochromatic LEDs can create an ideal environment for plant cultivation. The spectral output of the light can be tuned to deliver optimum growth and energy savings for a particular species of plant. As the world population continues to increase and more agricultural land is lost to urban development, greenhouses equipped with artificial lighting will play a more important role in plant cultivation.  OSRAM Opto Semiconductors offers monochromatic LEDs with peak wavelengths of 450nm, 465nm, 590nm, 625nm, 634nm, and 660nm which align with the absorption peaks for the important pigments involved in photosynthesis.

Algae Growth

Microalgae have shown great promise as a source in the production of biofuels, pharmaceuticals, health foods, and chemicals. Closed loop systems (PBRs) are one of the most common production systems for harvesting algae. Light cannot be stored in PBRs and is supplied continuously into the system. LEDs are an attractive alternative for artificial lighting because of their high energy efficiency at key wavelengths for the photosynthetic growth. Also, monochromatic LEDs eliminate the need for filters and complex cooling systems. Studies have shown that pulsed LED light results in an increase in cell concentration as compared to continuous light, resulting in increased algal productivity. LEDs, with their instant turn-on and turn-off function, can be used effectively to generate pulsed light at variable duty cycles.

Turtle Friendly

The evolutionary instinct of hatchling sea turtles pushes them towards the brightest source of light in view, usually the sun or the moon above the ocean horizon. However, their orientation is often disrupted by artificial light. Turtle hatchlings that do not enter the ocean suffer high rates of mortality. The sea-finding mechanism of these turtles is influenced by the characteristics of the light. Sea turtles are more sensitive to shorter wavelengths of light than to longer wavelengths. Lighting solutions that ensure that people can move about safely along beaches emit only longer wavelengths of light and are therefore considered as “turtle safe lighting”. LEDs that emit only specific wavelengths of light (> 560nm) require no filters and offer an attractive alternative to traditional lighting sources. The Florida Fish and Wildlife Conservation Commission has already come up with guidelines for approved sea turtle friendly lighting, using LEDs.

Aquarium

The purpose of lighting in an aquarium is to provide uniform illumination to the space underwater and to support the growth and sustenance of marine life. Light also serves as a decorative element. Similar to plant growth in terrestrial applications, LEDs offer optimal spectral output for growth of marine life. LED systems provide high intensity light with less radiant heat than traditional lighting sources, thereby reducing the cooling requirements. High color temperature LEDs with a broad band spectrum that simulates the appearance of sunlight with a blue spike for coral fluorescence are being widely considered for aquarium lighting. Also, LEDs are a point source of light, and as light penetrates the water and reflects with the movement of the water surface, they produce a more natural and eye-catching “shimmer” effect in the aquarium.

LEDs offer exciting new possibilities. These light sources offer advantages over traditional lighting sources that go well beyond energy savings. The unique properties of monochromatic LEDs offer a potential to create an impact and apply light to applications in ways it was never thought to be possible with incumbent technologies.

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