Optical characterization of ultrabright LEDs

Benavides, Juan Manuel; Webb, Robert H.

doi:10.1364/ao.44.004000

Cited by 14 publications

(11 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For an inhomogeneous intensity distribution on the virtual source, the calculation yields an effective radius parameter r S0 . Otherwise equation (2) remains unchanged. It should be noted that for an LED with large n, the value of r S can be much larger than r S0 and that the same relation is valid between r P and r P0 .…”

Section: Description Of the Methodsmentioning

confidence: 99%

Method for analysing luminous intensity of light-emitting diodes

Manninen¹,

Hovila²,

Kärhä³

et al. 2006

Meas. Sci. Technol.

View full text Add to dashboard Cite

Light-emitting diodes (LEDs) have built-in lenses that enable spatially limited light beams. The use of lenses increases the luminous intensity levels, but complicates accurate LED intensity measurements. A novel method for determining the luminous intensity of the LED is proposed. The method based on a modified inverse-square law describes the behaviour of an LED in terms of its luminous intensity, the radius of the virtual source and the location of the virtual source. The applicability of the method was tested for 17 LED types with different packages, angular intensity distributions and power levels. When applying the new method to the measurement data, instead of the inverse-square law of the point source, the distance dependence of apparent LED luminous intensity of up to 47% reduced to statistical variation of less than 1%.

show abstract

Section: Description Of the Methodsmentioning

confidence: 99%

Method for analysing luminous intensity of light-emitting diodes

Manninen¹,

Hovila²,

Kärhä³

et al. 2006

Meas. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Given the fact that the red LED has a smaller emitter area (Table 1), therefore a higher luminous density, and consequently a higher irradiance in the field of view (conserving étendue), we expected a higher SNR for the red LED compared to the blue one, after taking the different operating currents into account. The lower SNR could be due to the large variability in light output of LEDs (see and Benavides & Webb, 2005). Furthermore, the width of the point spread function and Rayleigh scattering favour blue LEDs.…”

Section: Resultsmentioning

confidence: 99%

“…Up to this current, the LED intensity steadily increased. Before implementing LEDs in a setup, several LEDs of the same colour should be compared to choose the brightest one, since LEDs from the same batch can vary by up to a factor of 3 in intensity (Benavides & Webb, 2005).…”

Section: Methodsmentioning

confidence: 99%

LED illumination for video‐enhanced DIC imaging of single microtubules

Bormuth

Howard

Schäffer

2007

Journal of Microscopy

View full text Add to dashboard Cite

Summary In many applications high‐resolution video‐enhanced differential interference contrast microscopy is used to visualize and track the ends of single microtubules. We show that single ultrabright light emitting diodes from Luxeon can be used to replace conventional light sources for these kinds of applications without loss of function. We measured the signal‐to‐noise ratio of microtubules imaged with three different light emitting diode colours (blue, red, green). The blue light emitting diode performed best, and the signal‐to‐noise ratios were high enough to automatically track the ends of dynamic microtubules. Light emitting diodes as light sources for video‐enhanced differential interference contrast microscopy are high performing, low‐cost and easy to align alternatives to existing illumination solutions.

show abstract

“…Note, however, that because of the complicated production process, there is a lot of variability between individual LEDs of the same model (Benavides and Webb 2005). For most experiments, when using LEDs for simple epifluorescence or other less demanding applications, this variability is unimportant.…”

Section: Choosing An Led For Imagingmentioning

confidence: 99%

Light-Emitting Diodes for Biological Microscopy

Sato¹,

Murthy²

2012

Cold Spring Harb Protoc

View full text Add to dashboard Cite

Various technological advances have made imaging an increasingly useful tool in the life sciences. Imaging techniques that move away from the limitations of wide-field microscopy have allowed deeper, higher-resolution imaging of thick biological tissue. Even within wide-field microscopy, advancements such as structured and sheet illumination, as well as improvements of biological probes, have led to better visualization of cells and their subcellular structures. The illumination source for wide-field microscopy, however, has remained relatively unchanged for decades, relying mainly on xenon, mercury, and halogen lamps. Light-emitting diodes (LEDs) have existed for more than 80 years, but their spectral range and output light flux have only recently become large enough for use in biological applications. This article presents the basic information necessary to build and to use an LED-based illumination source for microscopy. It also provides some useful resources about LED advancements. Although commercial LED-based illuminators for microscopy are available, custombuilt illumination systems can incorporate the latest LED chips into microscopes more quickly and inexpensively than is possible through the retail market.

show abstract

Optical characterization of ultrabright LEDs

Cited by 14 publications

References 3 publications

Method for analysing luminous intensity of light-emitting diodes

Method for analysing luminous intensity of light-emitting diodes

LED illumination for video‐enhanced DIC imaging of single microtubules

Light-Emitting Diodes for Biological Microscopy

Contact Info

Product

Resources

About