April 23, 2014

An Affirming Visit to The Vision Show in Boston on April 15, 2014

Joe Biden and other Boston politicians watch as a flag was raised on
the first anniversary of the bombings at the finish line of the Boston Marathon bombings.
Aside from the palpable energy of people remembering the victims of the tragic 2013 Boston Marathon bombings on its first anniversary, and the excitement of Joe Biden’s appearance at the finish line just outside the show , for me, the most interesting take-away from the Vision Show held at Hines Auditorium on April 15 and 16 was discovering the following:

1. Slow-motion video, produced by sensors with speeds in excess of 1,000 frames per second, require an enormous amount of light.

High frame rate sensors can be used to capture the movements of high-speed processes in a manufacturing setting. With the right volume of light (like that produced with the Hyperion), a Quality Assurance Engineer can replay these processes in slow-motion allowing them to better understand what actually happens in the manufacturing assembly line.
This level of inspection allows manufacturers to save millions of dollars through improved quality and productivity.
2. I am not alone on my quest to disprove the myth that LEDs are any cheaper or safer than their laser counterparts.
I was pleased to attend Wallace Latimer’s, Product Line Manager for Coherent, Inc. presentation. He discussed some of the many reasons why LED light sources are not only lower performance, but often drive more expensive solutions compared to laser based systems.

Among the points that Latimer made include:
• Unlike a laser light source, the half-bandwidth of an LED is large, requiring extra filtering for fluorophore excitation.

With an LED light source, light from the excitation spectrum will spill into the emission spectrum. An additional filter, called an excitation filter, has to be added to an LED light source in order to ensure valid results, adding costs that are often not accounted for when assessing light sources.

On the other hand, the sharp bandwidth of a laser does not require an excitation filter, which lowers complexity and system cost.

• LEDs force design compromises for product manufacturers serving the life sciences industry.

The automotive industry and general lighting applications commonly use LED light sources. Demand is so high that LED manufacturers are focused on these markets. These applications do not require the wavelengths to be as narrowly defined as in life sciences. As a result, it can be hard to order the specific LED wavelength for life science applications.

Compared to automotive and general lighting, the scale of demand for light sources within life sciences is small. As such, LED manufacturers have to resort to cost saving measures to serve this industry with practices like the wavelength binning process.

Manufacturers produce LEDs within their specified ranges (or “bins”) of wavelengths. This is not the case for laser manufacturers. Laser wavelengths have a much narrower range. The LED wavelength binning process forces product designers in the life sciences to amend their designs to fit the manufacturers’ specifications.

• The higher numerical aperture (NA) of an LED light source requires a larger investment in optics and power rating.

Given the diffuse nature of an LED beam, 2 additional investments are needed that are not necessary for a laser light source:

a. The investment in optics required for an LED to successfully focus on its target is significantly larger than that required of a laser light source.

b. Due to the less efficient beam, an LED requires a higher power rating than a laser to achieve the same illumination. As a result, the LED drive circuitry is larger, more costly and generates additional heat.
Indeed, it was an exciting trip to Boston and I plan on going again next year. Stay tuned (or join our mailing list) for a white paper comparing the relative safety of LEDs and lasers.

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