0. PhlatLight for fiber coupling
Luminus support and application examples
Confidential © 2010 Luminus Devices, Inc. All rights reserved.

1. Overview of Luminus support for fiber coupling applications
Luminus offers a specific product line that is tailored towards fiber coupling/etendue limited applications
The goal of these products is to maximize delivered lumens, not efficiency
Worksheet for a compound parabolic concentrator (CPC) is available as a reference design around these packages, along with direct support from Luminus applications engineers
Confidential © 2008 Luminus Devices, Inc. All rights reserved.

2. Product offerings for fiber coupling applications
CBM-360
Available in cool white only
2x2 array of 3mm x 3mm chips
Low thermal resistance (1.00 °C/W)
4,000+ lumens at 6.3 A (13.2 V)
CBT-90
Available in W (cool only),R,G,B
Single 3mm x 3mm chip
Low thermal resistance (0.92 °C/W)
2,000+ lumens at 13.5 A (3.3 V)
Key common characteristics
Very high flux density per unit area
Low etendue, no encapsulation (no dome lens)
Confidential © 2008 Luminus Devices, Inc. All rights reserved.

3. CPC design worksheet - basics
Based off of information presented in Nonimaging Optics, Winston, et. al. (2005) – ISBN #
Worksheet is available on the Luminus FTP site
Given a desired fiber diameter and numerical aperture, apply those parameters to the CPC to determine the input aperture size
A hollow reflective approach is recommended for high flux applications
Confidential © 2008 Luminus Devices, Inc. All rights reserved.

4. CPC design worksheet – main window
Fiber bundle/LED parameter description
CPC profile plot (for reference)
xyz free points for solid model import
Confidential © 2008 Luminus Devices, Inc. All rights reserved.

5. Application example using CPC worksheet
GOAL: To couple as much white light as possible into a OD 5mm, 0.66 NA fiber bundle
SOLUTION:
Use a hollow reflective approach to minimize etendue
Start with a CBT-90-W device (6500 K CCT)
Drive device at highest current possible for highest lumen output
0.66 NA corresponds to a half angle of 41 degrees (NA = n*sin(θ))
Input these basic parameters into worksheet, then generate solid model
Confidential © 2008 Luminus Devices, Inc. All rights reserved.

6. Confidential © 2008 Luminus Devices, Inc. All rights reserved.
5mm, 0.66 NA fiber example
Set θmax to 41 deg (0.66 NA)
Set n = 1.0 (hollow reflective)
Then change a’ (input of CPC) until a (fiber bundle radius) is the target—in this case, 2.50mm
This gives us the length of our CPC
Confidential © 2008 Luminus Devices, Inc. All rights reserved.

7. 5mm, 0.66 NA fiber example
Once parameters are set, copy and paste xyz data and save as *.txt file for import into any solid modeler
Output end (fiber side)
CPC curve
Reflective walls (part is hollow)
Input end (LED side)
Confidential © 2008 Luminus Devices, Inc. All rights reserved.

8. Concept images of configuration
Optic over LED – closeup
Full assembly
Note that optic is very small, since fiber bundle is very small
CPC should be as close as possible to LED
Even though LED seems large, this system is optimized given etendue constraints!
Confidential © 2008 Luminus Devices, Inc. All rights reserved.