We gather experts from the disciplines of physics (material, optics, lasers, liquid crystals), chemistry (liquid crystals, dichoric dyes, monomers, functional dopants), engineering (fabrication, processing, testing) and design (industrial, product, fashion, tactical) to create beautiful solutions to problems in light management.
To develop the right liquid crystal system, it is important to determine the optical properties of base materials and configurations.
AlphaMicron has significant expertise in design and testing of optical systems with a fully equipped optics lab including pulsed and CW (continuous wave) lasers, spectrophotometers, spectroflurometers, FTIR, and fast detectors. This allows us to fully characterize the electro-optical response of a device.
Near-eye Sunlight Management
e-Tint ®- Electronic Tint-on-Demand
Controlling sunlight is of paramount importance in a number of applications including eyewear, augmented reality displays, automotive, and architectural.
AlphaMicron’s e-Tint [LINK to e-Tint in Liquid crystal page] technology was specifically designed to address this issue. Using its patented guest-host technology coupled with its proprietary film fabrication process, AlphaMicron can create flexible functional films that can change their tint through application of a low voltage. This film can be laminated to a lens or glass to create an electronic tint-on-demand film. The operation window of the film can be tuned using AlphaMicron’s dichoric dyes [LINK to Specialty DYE in Material Page]. Depending on the application, the device can be designed to have a fail-safe operation in case of power failure – e.g. the device can be designed so that it switches to the clear sate within 0.1 seconds in case of power failure. In other applications, the device can be designed to switch to a tinted or black state in case the applied voltage stops.
AlphaMicron has used this technology to create the world’s first electronic eyewear LINK TO CTRL PAGE. This has been fielded and tested by the US Army and is now being placed in through Approved Protective Eyewear List. This provides the user with the ability to manually or automatically change the tint of the eyewear in 0.1 seconds- faster than a blink of an eye.
The technology is now being developed for augmented reality applications [LINK to AR PAGE} where the control of light is paramount. AlphaMicron is working with both military and private sectors to address this growing need.
In addition, AlphaMicron has teamed with DNP to create a large area films that can be used for automotive and architectural applications LINK TO SUNROOF AND WINDOWS.
Intense Light & Laser Light management
i-LID™ – Integrative Laser Intercept Device
Pilots all over the world have made urgent calls for powerful lasers to be banned, especially after the event in February of 2016, when a transatlantic flight was forced to return to Heathrow airport because the first officer was dazzled by a laser shortly after takeoff.
Between 2005 and 2014, more than 20,000 laser incidents were reported in US and almost 9000 occurred in UK. The increasing number of reports of laser events by pilots underscores the urgent need for ocular protection against laser radiation.
One obstacle to overcome in this system is to create a device that does not alter the visual perception of the pilot (colors) during takeoff and landing so as to ensure that the device does not interfere with the cockpit displays. As such, ideally, a system is needed that is only activated in the event of a hit by a laser.
AlphaMicron scientists have been working on developing an Integrated Laser Intercept Device or i-LID™– a liquid crystal-based switchable photonic band gap system engineered for aircrew eye protection against intense laser radiation.
The liquid crystal cells can be made to electronically protect against an individual laser wavelength or collectively against all wavelengths without having a permanent color in the eyewear that can conflict with cockpit displays.
Experimental – Optics Lab
AlphaMicron has in-house capability to test optical systems for a variety of applications ranging from electronic color filters to fast shutters for intense light protection. Its optics lab is equipped with spectrofluorometer capable of measuring the absorption, emission and excitation spectrum of any material for full spectroscopic analysis. In addition, it has several lasers which span the visible and near IR region of the spectrum and can be used to study and characterize the optical and electro-optic properties of material and prototypes.
AlphaMicron’s optical scientists are fully versed in vision science. They are intimately familiar with commercial and military specification and requirements placed on eyewear. To test the optical performance of any eyewear, it is necessary to measure a number of parameters such as refractive power, astigmatism, photopic and spectroscopic transmission, and haze. AlphaMicron can perform these measurements in accordance with ANSI z871. The lab can analyze the data from a these measurements and provide color co-ordinates and neutrality values needed for MIL Spec. In addition, we have the capability for testing the resolving power and distortion of an optical lens to ensure the devices provide highest quality optics to the user.
Theoretical – modeling of light propagation
AlphaMicron scientists have created computer simulations that can exactly model light propagation in a liquid crystal device including absorptive systems such as its e-Tint. The software carries a complete library of AlphaMicron material and dyes and can be used to create formulations based on performance requirements. The result is a system that can provide the expected electro-optic performance of a device and include such results as transmission in the on and off states, the polarization dependence, the colorimetric coordinates and spectrum of transmitted and reflected light.
Tunable LC Laser
One application of photonic bandgap materials [Link] is lasing in cholesteric liquid crystals. The self-assembly of liquid crystal coupled with the periodic nature of chiral system has allowed the use of liquid crystals as photonic bandgap materials. AlphaMicron scientists were among the first to observe lasing in photonic bandgap liquid crystals and have been pioneered this field, extending this to many other systems including polymeric and elastomeric liquid crystals.
Another breakthrough made by AlphaMicron scientists was the first observation of a material undergoing continuous wave (CW) lasing when excited by either a coherent laser light or by an incoherent LED light.
Continuous wave mirrorless lasing in cholesteric liquid crystals with a pitch gradient across the cell gap. OPTICS LETTERS, Vol. 37, No. 14, 2904 ( 2012) [Link to article]
Despite numerous efforts, continuous wave (CW) lasing in dye doped, one-dimensional (1D) photonic bandgap cholesteric liquid crystal (CLC) structures has not been previously reported, to our knowledge. Here we report on the observation of lasing in such structures under both coherent (laser) and incoherent (LED) CW light excitation. To achieve this effect, we used a 1D-photonic bandgap structure made of a polymer stabilized CLC with a pitch gradient across the cell thickness. A spectral reflectivity profile of such a CLC structure reveals local minima in the area within a photonic stopband and close to it. The realization of lasing pumped by low power CW light sources opens the possibility of all-organic, compact, tunable CW lasers for display and medical applications. © 2012 Optical Society of America