OPTICAL DEVICE WITH THERMALLY SWITCHING PHASE CHANGE MATERIAL

• Main Authors: BROUGHTON, Ben, BHASKARAN, Harish, HOSSEINI, Peiman
• Format: Patent
• Language: English; French; German
• Published: 11.07.2018
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

The present invention is notably directed to an optical device (1) comprising a layer structure (2) with: a thermally conducting, optical reflector (15); a thermally conducting spacer (14), which is transmissive to light and arranged above the reflector (15); and a phase change material (10), or PCM, arranged above the spacer (14) and having at least two reversibly switchable states, in which the PCM exhibits two different values of refractive index. The reflector (15), the spacer (14) and the PCM (10) are successively stacked along a stacking direction (z) of the layer structure. The optical device further comprises: a heating element (17), opposite to the PCM (10) with respect to the reflector (15), the layer structure (2) being configured so as to electrically insulate the PCM (10) from the heating element (17), while the heating element (17) is in thermal communication with the PCM (10) via the reflector (15) and the spacer (14); and a controller (19, 19a) configured to energize the heating element (17), so as to heat the PCM (10) and thereby reversibly change a refractive index of said PCM (10). The invention is further directed to related optical devices (notably devices comprising one or more pixels formed, each, by a set of layer structures such as described above) and actuation methods.