Microsoft Technology Licensing, LLC

Licentia Oy

Lauri Sainiemi

Tuomas Vallius

Tapani Levola

Pasi Saarikko

Tuomas Heikki Sakari Vallius

Marco Ilmari Mattila

Tapio Kotiaho

Samuli Franssila

Risto Kostiainen

Teemu Nissila

Raimo Ketola

In an optical display system that includes a waveguide with multiple diffractive optical elements (DOEs), gratings in one or more of the DOEs may have an asymmetric profile in which gratings may be slanted or blazed. Asymmetric gratings in a DOE can provide increased display uniformity in the optical display system by reducing the 'banding' resulting from optical interference that is manifested as dark stripes in the display. Banding may be more pronounced when polymeric materials are used in volume production of the DOEs to minimize system weight, but which have less optimal optical properties compared with other materials such as glass. The asymmetric gratings can further enable the optical system to be more tolerant to variations&#x2014;such as variations in thickness, surface roughness, and grating geometry&#x2014;that may not be readily controlled during manufacturing particularly since such variations are in the submicron range.

Diffractive optical elements with asymmetric profiles

Aspects described herein generally relate to a waveguide and/or an associated display apparatus. The waveguide includes a plurality of optical input ports configured to receive optical light, at least one optical output port configured to output at least a modified portion of the optical light, and a plurality of transmission channels, each coupled to one of the plurality of optical input ports and configured to transmit the optical light from a respective optical input port to the at least one optical output port. The plurality of transmission channels are arranged to cause the optical light diffracted from at least a first one of the plurality of transmission channels to partially overlap, at the at least one optical output port, with the optical light diffracted from at least a second one of the plurality of transmission channels.

Waveguide for generating overlapping images in a display module

In an optical system that includes a waveguide with multiple diffractive optical elements (DOEs) incorporating diffraction gratings, light exiting a trailing edge of an upstream DOE enters a leading edge of a downstream DOE. One or more of the DOEs may include a leading and/or a trailing edge that have a graded profile. At a graded trailing edge of an upstream DOE, grating height smoothly decreases from full height to shallow height as a function of the proximity to the trailing edge. At a graded leading edge of the downstream DOE grating height smoothly increases from shallow height to full height as a function of distance away from the leading edge. By reducing a sharp boundary at the interface between the upstream and downstream DOEs, the graded profiles of the DOE edges enable optical resolution to be maintained decreasing sensitivity to misalignment between the DOEs that may occur during manufacturing.

Diffractive optical elements with graded edges

In an optical display system that includes a waveguide with multiple diffractive optical elements (DOEs), one or more of the DOEs is configured with gratings that have varying depth and varying directions for depth modulation, in which the modulation direction is aligned with the steepest change (i.e., slope) of grating depth. Depth modulation direction may change at a point of transition between different regions in the DOE. For example, with a zero axis being defined along a line parallel to a long side of a DOE, the depth modulation direction can change from a negative angle, with respect to the axis in the plane of the waveguide in one region, to a positive angle in another region, or vice versa. By varying depth modulation direction in a DOE, display uniformity in the optical display system may be increased.

Diffractive optical elements with varying direction for depth modulation

Microfabrication processes and apparatuses for fabricating microstructures on a substrate are disclosed. The substrate has a current diffraction grating pattern formed by current surface modulations over at least a portion of the substrate's surface that exhibit a substantially uniform grating linewidth over the surface portion. An immersion depth of the substrate in a fluid for patterning the substrate is gradually changed so that different points on the surface portion are immersed for different immersion times. The fluid changes the linewidth of the surface modulations at each immersed point on the surface portion by an amount determined by the immersion time of that point, thereby changing the current diffraction grating pattern to a new diffraction grating pattern formed by new surface modulations over the surface portion that exhibit a spatially varying grating linewidth that varies over the surface portion.

Microfabrication

The invention relates to an electrospray ionization (ESI) device for forming a stream of ionized sample molecules. The device comprises a sample introduction zone for receiving a liquid-form sample, a tip for spraying the sample into aerosol or gaseous form, and a flow channel connecting the sample introduction zone and the tip. According to the invention, the flow channel comprises an array of transversely oriented microstructures adapted to passively transport the liquid-form sample introduced to the sample introduction zone to the tip by means of capillary forces. The invention concerns also a manufacturing method and applications of the ESI device, in particular mass spectrometry. The device can be used without external pumping of sample liquid.

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Espoo, Finland

Lauri Sainiemi