Abstract: A method for identifying and quantifying organic or biochemical substances in a fluid medium using a nanogap sensor is disclosed. A nanogap sensor with two electrodes of different materials is used, a respective probe molecule is bonded to each electrode and the free remainder of the probe molecules have at least one bondable group with specificity to a substance or analyte. The analyte has at least two binding sites and passes selectively out of the fluid medium, binds to the free ends of the probe molecules to form a bridge, modifying the impedance between the electrodes.

Abstract: A method for identifying and quantifying organic or biochemical substances in a fluid medium using a nanogap sensor is disclosed. A nanogap sensor with two electrodes of different materials is used, a respective probe molecule is bonded to each electrode and the free remainder of the probe molecules have at least one bondable group with specificity to a substance or analyte. The analyte has at least two binding sites and passes selectively out of the fluid medium, binds to the free ends of the probe molecules to form a bridge, modifying the impedance between the electrodes.

Abstract: A tunable [tunable] surface-emitting laser diode in which in the manner of the TTG laser diode an active layer (5) and a tuning layer (3) are arranged transverse to one another between contact layers (2, 6) and are separated from one another by a central layer (4), with the result that given suitable doping of the surrounding semiconductor material these layers can be driven separately, and in which above a region provided for generating radiation the semiconductor material has on the surface a spatial periodic structure which is provided with a thin metallic film (7), with the result that during operation of the laser diode radiation is emitted directionally from the surface by means of exciting surface plasmon polaritons, and that this emission direction can be varied by tuning the wavelength of the radiation.

Abstract: A surface-emitting laser diode with an active layer (3) between contact layers (2, 4) and reflector arrangements (9, 19) provided for a vertical resonance condition, in which the surface of the semiconductor material is provided with a spatial periodic structure, which is intended for the excitation of surface plasmon polaritons, and is covered with a thin metal film (5).