News | Sep 26, 2017
16 Photonics Technologies You Probably Didn’t Know Are Available
Call it a ménage à lumière
Back in the 1970s, the Army developed laser tag to enhance battle drills. Military scientists and engineers have put photonics to work doing more since then. And much of that work has led to patented technologies that are now available to businesses that would turn them into new products and services.
Air Force researchers have leaped closer to quantum communications with the development of an optical system that can route or exchange entangled photon states and properties. Using a co-linear entangled source, the system selectively manifests frequency entangled or polarization entangled photons suited for secure quantum key distribution (QKD) applications with shared keys and provable security. It also enables a complete entangled state to be routed to either user by selecting the input frequencies to be both congruent, or incongruent. Unique features are selectable entanglement and routing, compact size, and integrated construction for telescopic compatibility.
Army researchers have developed a beam splitter which is spherical rather than cubic, which can be rotated to alter the angle of incidence. This tuning capability is faster and more precise than the repositioning of optical components under current methods.
Navy researchers have developed a single laser atom interferometer that is less-complicated, smaller, and less-expensive. The core of the device is a modulated laser driven by direct current for frequency tuning, and an alternating current with two radio frequencies that can generate repump and Raman frequencies, such that only one laser is needed to produce all the frequencies required for operation.
Outlaws? No, but the Air Force Research Laboratory–Sensors Directorate has developed a patent-pending, universal polarization converter capable of converting unpolarized light into pure polarized light of any kind with 100 percent efficiency. Check your physics handbook folks, that breaks the Law of Malus, which states that the maximum conversion efficiency of unpolarized light into polarized form cannot exceed 50 percent. Applications for the converter include coherent beam combination, sensor enhancement, LCD brightness improvement, wavelength division multiplexer loss reduction, optical switches and filters, LIDAR and radar sources, and improved antenna designs. Interested?
Navy researchers have developed an electro-optical identification, jamming, and disabling system comprised of an optical source emitting a signal towards an EO device, a detector to capture the optical energy reflected from the EO device, and a controller analyzing the detected optical energy to determine whether the EO device is authorized or not.
Whoa! Air Force researchers figure out how to make high-performance doped solid optical materials using hot isostatic pressing to drive the diffusion of transition metal ions into chalcogenide laser host crystals, such as chromium, iron , cobalt, or nickel into zinc selenide. The resulting crystals provide an unparalleled increase in performance over the current state of the art with significantly reduced manufacturing cost and increased throughput.
Lidar receiver performance is directly related to the effective aperture of the input optical system. A larger aperture increases the amount of light energy collected and increases the effective range of the system. However, the field-of-view (FOV) of the optical system is inversely proportional to the effective aperture, practically limiting the size of the effective aperture for a given FOV. Army researchers have solved this dilemma by dividing the overall FOV into smaller pieces, with each smaller piece covered by a separate receiver element that can have a larger effective aperture due to its smaller FOV. When properly combined, the small FOV receivers increase the overall system performance over that which can be achieved with a single, wide FOV receiver.
Speaking of LiDAR, this hybrid system designed at the Naval Air Warfare Center Aircraft Division–Patuxent River pairs it with radar to detect cancerous tumors in humans. It uses continuous wave light that is modulated at frequencies up to 60 GHz. The system filters the return signals from the surrounding tissue at a subcarrier modulation frequency so it can reject noise in the scattered lights, while at the same time retaining the coherent, unscattered and modulated light information for detecting the tumors.
To advance underwater drones, Navy researchers have developed a low cost optical imager utilizing a bistatic geometry where the laser and receiver are decoupled. An imaging laser beam is steered with a MEMS scanner to sequentially illuminate an object. A distant receiver collects the reflected laser light and reconstructs the image. Communications information, including a synchronization sequence, is encoded onto the modulation that is used by the receiver to build the image. Hint: this pairs perfectly with “Extended range optical imaging system for use in cloudy air or water.”
The Army invented a chirped AM architecture, low-cost CW semiconductor diode lasers and range-Doppler processing to measure both the range and velocity of a moving target. It features a significant increase in sensitivity (10^4) that can be used to obtain LiDAR operation with some combination of longer range, lower laser power, and/or smaller receiver aperture area. Note: this technology is available via express licensing.
Navy researchers have developed novel chromophores–benzo-fused, five-membered heterocyclic (BFFH) dyes which provide a higher electro-optical coefficient for optical absorption in the 1530-1570 nm communications window. The dyes have increased Beta (upwards of 2x) and exhibit no red shift comparable to pentanoic dyes (a phenylene dye with an additional ene unit). These chromophores provide communications engineers the option of constructing smaller devices, using a lower operating voltage, and measuring a weaker electric field with the device than has previously been possible. A total of 16 BFFH dyes have been designed and synthesized, many with a slightly smaller dipole moment.
Air Force researchers have developed a Raman amplifier having a novel design enabling high-Raman conversion efficiencies and output powers in addition to linewidths which are controllable by the seed source. In this invention, a RE doped Raman amplifier is spliced directly onto a Raman resonator system. The RE doped amplifier is both seeded with the initial signal and the desired output signal through a wavelength division multiplexer (WDM). Because of power limitations associated with the WDM, it is necessary to amplify the initial signal via a downstream amplifier. This amplifier may consist of one or multiple stages with each stage being pumped with diodes. The desired output signal and amplified initial signal are then both injected into the Raman resonator(s) where multiple orders of Stokes are generated in one or more Raman amplifiers. The desired signal passes through the system and is amplified by the Stokes signal.
Common remote sensing technologies, specifically LiDAR, struggle to discern color and texture at a distance. This Navy invention advances the state-of-the-art in remote sensing with enhanced color rendering steps from an optical sensor working alongside a lidar sensor. The technology pushes intensity imagery (an optical to electronic signal converter) through a MACH filter and then overlays that onto to a 3-D wiregrid model. The model is built up from a multitude of sensor data of the target of interest. Users input the likely classification of the target, i.e. a ship, and the database begins its image comparison against stored images of ships. Intensity data is used to compare a synthetic image with the observed image on a pixel-by-pixel and average pixel intensity basis.
Air Force researchers have developed devices based on photoconductive or photovoltaic materials that automatically sense incident light and tune the device accordingly for various absorption, reflection, or scatter filtering applications. Knowledge of the wavelength beforehand is not required as these light valves automatically self-tune based on the incident radiation at the time. This technology is application-flexible and can operate with laser beams and other focused or unfocused radiation sources.
This technology developed by Navy researchers relates to an active sensor or video system with two sources of scene illumination, which obtains a 3-D surface from the scene imaged by the sensor system. Pixel data of the intensity images and the distances between the illumination source and the sensors are processed to determine the 3-D location of each pixel thereby obtaining the 3-D map of the surface of the imaged scene.
Navy researchers have addressed the relaxation time problem, the time between excitement by the laser and the return to the ground state, of single, uncharged quantum dots for creating a single photon. Instead of using one uncharged QD, two singly-charged quantum dots that are separated by a thin tunnel barrier are utilized. This coupled quantum dot system is referred to as a quantum dot molecule. The energy levels of the quantum dot molecule are effectively a three-level system in an optical cavity. In a three-level system, a laser beam can trigger a Raman single photon, which is shifted from the laser beam.
Interested in using these technologies to grow your business? Get in touch with one of our experts for no-cost licensing assistance. Want more? Search TechLink’s database, which includes more than 600 photonics technologies, for more opportunities to grow your business.