Research Project Information

Research Project Summary Information

Ultra-Thin Energy Efficient Luminaire(ST9423-1)

RPC Photonics Inc.


Linear and CFL lighting systems are the dominant lighting used in most commercial buildings, accounting for approximately 56% of the lighting energy consumed in the commercial sector. Fluorescent lamps are diffuse sources and good for general, ambient lighting. Halogen reflector lamps are used for applications requiring directional light because of their effectiveness as a directional light source, but these lamps are very inefficient, with efficacies of less than 65% (6-12 lm/W). Halogen sources make up 14% of the lighting energy consumed in commercial buildings, and 11% of lighting energy consumed in homes. LED replacements for reflector lamps are available but these do not perform well in existing luminaries because of the thermal management and optical requirements of LEDs. There are currently no luminaries specifically designed for LEDS.

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Project Description

Project goals included designing LED (light emitting diode) luminaries to replace downlights, accent lighting, and wallwash luminaries using incandescent, halogen, and compact fluorescent (CFL) lamps. Specific project tasks include (1) evaluation of commercially available LEDs to determine the LEDs’ most suitable for use with an LED downlight luminaries, in terms of color and efficacy, (2) design of a prototype luminaries, (3) component manufacture, (4) prototype evaluation, and (5) selection of a manufacturer to commercialize the product.


LEDs are very small light sources that can be precisely controlled optically. LEDs' small sizes give flexibility in luminaries design and, when used with different lenses, the same luminaries can be used for ambient and directional lighting. Significant advances are being made in LED efficacy improvements, and LEDs have already been demonstrated to attain 90 lumens/W in laboratory studies.

Project Results

The Contractor evaluated several high brightness LEDs over the course of the project, including red, green and blue (RGB) LEDs, and the Cree XR-E was chosen. Two luminaries’ design types were developed and evaluated; a light guide structure and a backplane diffuser. Due to the high cost of mold-tool fabrication, the backplane luminaries approach using direct illumination of the Contractor's trademarked Engineered Diffuser was selected. Three diffusers were prototyped and all had high efficiencies, ranging from 90 to 92%. The light output from the luminaries at 300 mA ranged from 739 lm to 753 lm, which is greater than the light output of a comparable 60-W incandescent downlight. It is approximately 650 lm, and it is possible to under-drive the LEDs to 255 mA for a light output of 650 lm, which will result in higher LED luminous efficacy and lower operating board temperature. RPC Photonics and the LRC created a feasibility demonstration model of the ultra-thin LED-based luminaries. The LED luminaries will replace luminaries that use incandescent, halogen, and compact fluorescent lamp (CFL) technologies. RPC Photonics is reaching out to several potential lighting fixture manufacturers in New York State to manufacture and distribute the product. RPC Photonics has also requested the assistance of The Lighting Cultivator (dba Linc) to locate a manufacturing partner.


RPC Photonics Inc.
330 Clay Rd
Rochester, NY 14623

Principle Investigator

Rose Peet

Universities Involved

Rensselaer Polytechnic Institute


Project Type:

Product Development

Technologies Types:

Building Systems
Solid State

NYSERDA Contact Information

Marsha Walton


R&D - Buildings Research

Contract Details

Start Date: 1/11/2010
Project Status: Active
Contract Number: ST9423-1

Last Updated: 3/6/2012 1