One of the most useful of these wavelengths is infrared, the waves of which stretches between 760 nanometers to 100,000 nanometers (the name comes from the fact that it’s just longer than the color red, the longest wavelength in the visible spectrum). Infrared is used in all sorts of applications—especially imaging—and being able to manipulate this wavelength can produce better results.

That’s why scientists from North Carolina State University worked to successfully “squeeze” infrared light to 10 percent of its wavelength while maintaining its frequency. The researchers achieved this breakthrough by using a special class of oxide membranes rather than bulk crystals, which can traditionally only barely squeeze infrared light. The results of this study were published earlier this month in the journal Nature Communications.

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Based on the answers to my question Can I use a LCD as backlight for acquiring film using a DSLR? and the link provided about optimal light sources for negative film I would like to build a light source which emits no orange at all, so that the orange of the film won't be recorded by the camera.

To understand what happened next requires a brief foray into Particle Physics 101. Photons are particles of light and the fundamental unit of the electromagnetic spectrum. Phonons, on the other hand, are “a fancy word for a particle of heat” (according to MIT), but can also be thought of as sound energy. Both photons and phonons deal in the realm of excitations and vibrations—however, when an infrared photon is coupled with an optical phonon (a.k.a. a phonon that can emit or absorb light), then it forms a quasi-particle called a “phonon polariton.” It’s these polaritons that do the squeezing.

“Theoretical papers proposed the idea that transition metal perovskite oxide membranes would allow phonon polaritons to confine infrared light,” Liu said. “And our work now demonstrates that the phonon polaritons do confine the photons, and also keep the photons from extending beyond the surface of the material.”

I have no experience on the topic and the goal is to obtain a uniform light field. It will be diffused light, not collimated. Collimated may be much more difficult so I can skip it for now.

I would intermix LEDs of the different wavelengths, but should I put sources on the side walls of a white light box which has diffusing walls and back surface? should the box be square or circular? circular may benefit from the 1/r rule and result in a more homogeneous light on the back wall/diffuser. Or should I put them not on the sides but on the back side, behind one or two diffusers? or maybe on the walls but directed to the back?

Uniformlight meaning

“We’ve demonstrated that we can confine infrared light to 10% of its wavelength while maintaining its frequency—meaning that the amount of time that it takes for a wavelength to cycle is the same, but the distance between the peaks of the wave is much closer together,” Yin Liu, a co-author of the study, said in a press statement. “Bulk crystal techniques confine infrared light to around 97% of its wavelength.”

CCS inc

Likely the best lamphouse design would be collimated light. Meaning the light rays from the light source arrive at the negative / slide as parallel rays that uniformly illuminate. The design of such a lamphouse mimics the condenser enlarger. These utilize two plano convex “condenser lenses”.

Darren lives in Portland, has a cat, and writes/edits about sci-fi and how our world works. You can find his previous stuff at Gizmodo and Paste if you look hard enough.

How can I arrange them to build a homogeneous light box? 3D printing is possible so I don't need to be restricted to existing products.

To test this new device and see if it could “squeeze” infrared light to a useful degree—an idea that had insofar only been theoretical, according to the researchers—the team turned to the Advanced Light Source at the Lawrence Berkeley National Laboratory. This research facility runs an infrared program capable of probing materials at micro- and nano-scales. The team performed synchrotron near-field spectroscopy on the thin strontium titanate film, and what was once theoretical became very much practical.

A mirror box integrating chamber is often used for this application. Four mirrors are mounted together at the edges to form a box or tube. The light is directed into this chamber, it reverberates about. In the process it arrives at the negative / slide totally diffused.

Such integrating chambers cannot eliminate dust spots, but they totally diffused light acts to suppress the visibility of dust on photo materials. Let me add that the end of the mirror tunnel, next to the negative / slide is covered with milk glass or milk plastic (white translucent diffuser).

The human eye is a natural wonder, the result of millions of years of evolutionary tinkering, and... remarkably limiting. Our eyes can only see a small sliver of the electromagnetic spectrum, so to see anything else requires relying on technology that can glimpse these “invisible” wavelengths.

Advanced illumination

The best design for dust suppression is a lamphouse that delivers a uniform light that is highly diffused. This will be an integrating chamber. This can be a box, or a sphere painted flat white. Light is allowed to enter the integrating chamber via holes in its walls. The light reverberates about and arrives at the negative / slide with no apparent direction.

Such a lamphouse has the undesirable trait of showing every speck of settled dust. Best is a lamphouse that suppresses dust spots.

Liu and his colleagues said that this breakthrough could lead to a whole new generation of infrared imaging technologies and thermal management devices. “Imagine,” Liu said, “being able to design computer chips that could use these materials to shed heat by converting it into infrared light.”

According to the statement, the researchers made use of “transition metal perovskite materials” in the study. Using pulsed laser deposition—which involves a powerful pulse laser beam in a vacuum chamber—the researchers grew a 100-nanometer-thick membrane made of an oxide of strontium and titanium called strontium titanate (SrTiO3). Once completed with very few flaws, the films were removed from that substrate and placed on a silicon substrate.