Max-planck-gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

Other

Degussa - Huls Ag

Ulrich Gosele

Christoph Batz-Sohn

Stephen Wesley Leonard

Ralf Wehrspohn

Henry M Van Driel

Jorg Schilling

Stefan Senz

Gertrud Krauter

The present invention provides a method for fast switching of optical properties in photonic crystals using pulsed/modulated free-carrier injection. The results disclosed herein indicate that several types of photonic crystal devices can be designed in which free carriers are used to vary dispersion curves, stop gaps in materials with photonic bandgaps to vary the bandgaps, reflection, transmission, absorption, gain, or phase. The use of pulsed free carrier injection to control the properties of photonic crystals on fast timescales forms the basis for all-optical switching using photonic crystals. Ultrafast switching of the band edge of a two-dimensional silicon photonic crystal is demonstrated near a wavelength of 1.9 &#x3bc;m. Changes in the refractive index are optically induced by injecting free carriers with 800 nm, 300 fs pulses. Band-edge shifts have been induced in silicon photonic crystals of up to 29 nm that occurs on the time-scale of the pump pulse. The present invention also provides a method of producing a virtual or temporary photonic crystal using free carrier injection into pure semiconductors, bulk or thin film, in which the carriers are generated in patterns which create a patterned refractive index contrast used to steer light beams in the semiconductor while it is being pulsed.

Method of varying optical properties of photonic crystals on fast time scales using energy pulses

A process for joining two solid bodies, in particular of silicon. via the substantially smooth surfaces that have first of all been coated with a monomolecular layer of a sulfur-containing organosilane, and the resultant solid bodies, which may be used in microelectronics or micromechanics.

Process for joining two solid bodies and the resultant structural element

A method for the releasable bonding of at least two wafers (10, 12), for example of two silicon wafers (silicon discs), or of a silicon wafer and a glass wafer, or of a semiconductor wafer and a cover wafer, by a wafer bonding method in which the surfaces to be brought into contact with one another are at least substantially optically smooth and flat. Prior to bringing the surfaces of the wafers (10, 12) into contact, one or more drops of a liquid are applied to at least one of the surfaces, and the wafer bonding method is carried out at least substantially at room temperature, or at a somewhat higher temperature, or optionally at a somewhat lower temperature. The wafers (10, 12) which are bonded together can easily be separated from one another in that at least the liquid enclosed between the wafers (10, 12), which are bonded to one another, is exposed to a temperature lying substantially above the bonding temperature at which the liquid vaporizes. A wafer structure is also disclosed.

Method for the releasable bonding and subsequent separation of

A method of manufacturing microstructures in which a hollow cavity is formed in a first wafer, in particular, a silicon wafer, and the hollow cavity is, covered over by a second wafer, which is in particular, also a silicon wafer, by a wafer bonding process in vacuum for the formation of an enclosed hollow cavity, wherein the wafer bonding is carried out in an ultra-high vacuum in order to achieve the smallest possible internal pressure in the hollow cavity of less than 0.1 mbar. The surfaces of the wafers which are to be brought into contact with one another are treated by a surface cleaning process in order to produce at least substantially pure surfaces, i.e. surfaces which consist substantially only of the material of the respective wafer and which are at least substantially free of H.sub.2 O, H.sub.2 and O.sub.2. A microstructure is also claimed.

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Halle, Germany

Ulrich Gosele