A device for selective transmission of an optical signal with variable adjustable frequency, comprising: - an input coupling facet for coupling an optical signal in, - an electro-optical modulator configured as a first optical waveguide for modulating an optical signal coupled in, the electro-optical modulator cooperating with the input coupling facet and being connected via electrical contacts with a first drive circuit, wherein the first waveguide is configured from a material having an optical transmission that is increased through injection of electrical charge carriers, - wherein the first drive circuit has at least one electrical switching element for injection of electrical charge carriers into the first waveguide for a corresponding predetermined time interval and with a predetermined repetition frequency, - an optical amplifier configured as a second optical waveguide (1, 2) for amplification and/or contrast enhancement of the optical signal coupled from the first waveguide into the second waveguide (1, 2), wherein the first waveguide is arranged between the input coupling facet and the second waveguide (1, 2), and wherein the second optical waveguide (1, 2) is connected via electrical contacts with a second drive circuit, wherein the second drive circuit has at least one switching element, and - an output coupling facet for coupling the optical radiation out of the second waveguide (1, 2), - wherein the spacing between the switching element of the first drive circuit and the first optical waveguide is less than 3 mm, characterised in that the first optical waveguide has a first absorber section, a pulse picker section and a second absorber section, wherein the first drive circuit is configured to increase the optical transparency of the pulse picker section through injection of electrical charge carriers, and wherein the first drive circuit is furthermore configured to apply an electric field in the opposite direction to the first absorber section and the second absorber section while the charge carriers are injected into the pulse picker section. - an input coupling facet for coupling an optical signal in, - an electro-optical modulator configured as a first optical waveguide for modulating an optical signal coupled in, the electro-optical modulator cooperating with the input coupling facet and being connected via electrical contacts with a first drive circuit, wherein the first waveguide is configured from a material having an optical transmission that is increased through injection of electrical charge carriers, - wherein the first drive circuit has at least one electrical switching element for injection of electrical charge carriers into the first waveguide for a corresponding predetermined time interval and with a predetermined repetition frequency, - an optical amplifier configured as a second optical waveguide (1, 2) for amplification and/or contrast enhancement of the optical signal coupled from the first waveguide into the second waveguide (1, 2), wherein the first waveguide is arranged between the input coupling facet and the second waveguide (1, 2), and wherein the second optical waveguide (1, 2) is connected via electrical contacts with a second drive circuit, wherein the second drive circuit has at least one switching element, and - an output coupling facet for coupling the optical radiation out of the second waveguide (1, 2), - wherein the spacing between the switching element of the first drive circuit and the first optical waveguide is less than 3 mm,