Abstract: A the vertical-cavity surface-emitting laser includes a stripe-shaped active medium (10) having an emission maximum at a first wavelength (?1), wherein a first reflector (18) is arranged below the stripe-shaped active medium (10) and a second reflector (20) is arranged above the stripe-shaped active medium (10), with the first reflector (18) facing the second reflector (20), wherein the first reflector (18) and a second reflector (20) have a reflectivity maximum in the region of the first wavelength (?1), wherein a third reflector (12) and a fourth reflector (13) are each arranged on a side above or next to the stripe-shaped active medium (10), wherein the third reflector (12) faces the fourth reflector (13), and wherein the third reflector (12) and the fourth reflector (13) have a reflectivity maximum in the region of a second wavelength (?2), wherein the first wavelength (?1) is greater than the second wavelength (?2).

Abstract: The invention relates to a free-standing semiconductor substrate as well as a process and a mask layer for the manufacture of a free-standing semiconductor substrate, wherein the material for forming the mask layer consists at least partially of tungsten silicide nitride or tungsten silicide and wherein the semiconductor substrate self-separates from the starting substrate without further process steps.

Abstract: A the vertical-cavity surface-emitting laser includes a stripe-shaped active medium (10) having an emission maximum at a first wavelength (?1), wherein a first reflector (18) is arranged below the stripe-shaped active medium (10) and a second reflector (20) is arranged above the stripe-shaped active medium (10), with the first reflector (18) facing the second reflector (20), wherein the first reflector (18) and a second reflector (20) have a reflectivity maximum in the region of the first wavelength (?1), wherein a third reflector (12) and a fourth reflector (13) are each arranged on a side above or next to the stripe-shaped active medium (10), wherein the third reflector (12) faces the fourth reflector (13), and wherein the third reflector (12) and the fourth reflector (13) have a reflectivity maximum in the region of a second wavelength (?2), wherein the first wavelength (?1)) is greater than the second wavelength (?2).

Abstract: The invention relates to a free-standing semiconductor substrate as well as a process and a mask layer for the manufacture of a free-standing semiconductor substrate, wherein the semiconductor substrate self-separates from the starting substrate without further process steps.

Abstract: A receiving device having an input receiving an input signal which includes a useful signal and an interference signal, a demodulator coupled to the input and generating a demodulated output signal from the input signal, which has an adjustable operating point, and a detector coupled to the demodulator and determining from the output signal a characteristic value representing a power level of the interference signal and setting the operating point of the demodulator as a function of the characteristic value.

Abstract: A semiconductor laser has an antiresonant waveguide (10), which is formed by a layer sequence applied to a substrate (1). The layer sequence has outer waveguide regions (2, 8), reflection layers (3, 7), and a waveguide core (11) with an active layer (5). With this structure, semiconductor lasers with only slight vertical beam divergence and with a large beam cross section can be produced.

Abstract: An offset voltage at an output of a differential amplifier is compensated for by a control circuit having a digital setting device. The control circuit has a control device which is controlled by an offset voltage of the differential amplifier and which feeds an offset compensation signal into the differential amplifier. Compared with analog compensation with an external storage capacitor, temporal drift effects do not distort the offset compensation on the differential amplifier. The described principle can be applied, for example, in radio frequency receiver circuits.