VerLASE Wins sixth Patent on colour conversion
VerLASE Technologies has been awarded US Patent No. 9,431,794 on the use of 2D materials to grow semiconductor structures that can downconvert InGaN-based blue/violet emitters into any colour in the visible spectrum.
The patent expands the Company's IP portfolio to six US patents now issued, with others pending, covering use of Quantum Wells (QWs) and novel resonators to make colour converting chiplets principally for the emerging Augmented Reality (AR) market.
In AR architectures, sophisticated optical or holographic waveguides can now superimpose a microdisplay image onto a user's field of view, or an image can even be scanned directly onto a user's retina, but forming such micro-images bright enough to see against a bright daylight background in full colour and high resolution remains a significant challenge.
The OLED microdisplays used today principally in a self-contained Virtual Reality (VR) environment simply cannot meet requirements for such next gen AR microdisplays; there are NO good solutions to efficiently render such micro-images at high enough brightness, at high resolution and in full colour.
The present patent builds on the company's prior patents to show how II-VI and other semiconductor materials can be grown in the very difficult-to-achieve Wurtzite crystal phase by using certain 2D materials as templates, a feat the Company had also shown experimentally, believing it to be the first group to have ever done so. Such II-VI films have previously been commonly grown in the less stable Zinc Blende phase with high defect densities limiting their broader use.
Wurtzite phase makes possible robust, high quality, near defect free QWs used in the Company's innovative Chromover(tm) colour down-conversion technology. Using a novel resonator design, Chromover(tm) can be designed to efficiently emit omnidirectional or directional spontaneous LED light, the latter in a narrow, low-étendue cone angle; or, if excited by a laser diode, to lase as an optically pumped VCSEL (Vertical Cavity Surface Emitting Laser). Spectral properties can also be tailored to a degree, with some control of coherence to mitigate speckle, a significant problem in projecting images with lasers.
A single Chromover chiplet can be pixelated and support multiple colours (RGB) forming a colour converting layer for emerging InGaN-based microLED displays. Such microLED displays are ideally suited for AR: far brighter, more efficient and much longer lived than the OLED microdisplays used in VR. They require efficient colour conversion, however, but the traditional phosphors and QDs used for colour with LEDs are not practical. Moreover, the diffractive or holographic waveguide optics used in the leading AR architectures are highly sensitive to input angle and spectral width, making imperative some directional and spectral control of the input source light.
"This is a key step to realising the vision of untethered, stylish glasses that can project high resolution, full colour images onto your field of view with long battery life for an amazing user experience," said Ajay Jain, the inventor and CTO, adding that "all the manufacturing processes are readily available, commercially scalable, and can be outsourced." The Company has been working with leading players in the VR /AR space to better define market requirements.
VerLASE Technologies LLC operates semi-virtually with partners around the world. It spun out of Versatilis LLC in 2013 with an investment by Wakley Limited, a Hong Kong based private investment group.
Founded by Versatilis' principals George Powch (CEO) and Ajay Jain (CTO), it focuses on technology development for VCSELs, LEDs, principally focused on AR and projector markets. It is also extending novel 2D layered materials technology developed by Versatilis in part with the help of numerous Small Business Innovation Research (SBIR) Awards from Government Agencies including DOE, DARPA, ONR and ARL.