Device and method for selective transmission of an optical signal

A method for producing pulsed laser radiation by

• coupling an optical signal into a device for selective transmission of an optical signal with variable adjustable frequency, wherein the device comprises:
• 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 formed of a material having an optical transmission that is increased through injection of electrical charge carriers,
• wherein the first drive circuit comprises 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 formed as a second optical waveguide for amplification and/or contrast enhancement of the optical signal coupled from the first waveguide into the second waveguide, wherein the first waveguide is arranged between the input coupling facet and the second waveguide, and wherein the second optical waveguide is connected via electrical contacts with a second drive circuit, wherein the second drive circuit comprises at least one switching element, and
• an output coupling facet for coupling the optical radiation out of the second waveguide,
• wherein the spacing between the switching element of the first drive circuit and the first optical waveguide is less than 3 mm,
• wherein the first optical waveguide comprises 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 to the first absorber section and the second absorber section an electric field in the opposite direction while the charge carriers are injected into the pulse picker section;
• the method comprising the steps of:
• intermittent injection of electrical charge carriers into the first waveguide for selective transmission of the coupled optical signal,
• wherein the selected optical signal is amplified in the second optical waveguide and/or the contrast of the selected optical signal in the second optical waveguide is increased.