A method for frequency stabilization of semiconductor lasers, the method comprising: forming a first contact surface of a semiconductor single-frequency laser chip for a tunable laser-based trace gas analyzer, especially for a tunable diode laser absorption spectrometer, to a target surface roughness, the target surface roughness being less than 100·10 -10 m rms, wherein a metallic diffusion barrier layer is applied to the first contact surface ; applying a metallization layer comprising 600·10 -10 m of titanium to the first contact surface prior to applying the metallic diffusion barrier layer; applying the metallic diffusion barrier layer to the titanium layer, wherein the metallic diffusion barrier layer includes multiple layers of differing materials, wherein a first metallic diffusion barrier layer comprises 1200·10 -10 m thickness of platinum; applying a solder preparation layer comprising approximately 2000·10 -10 m to 5000·10 -10 m thickness of gold to the metallic diffusion barrier layer subsequent to applying the metallic diffusion barrier layer and prior a soldering; soldering the semiconductor laser chip along the first contact surface to a carrier mounting using a solder composition , the soldering comprising melting the soldering composition by heating the soldering composition to less than a threshold temperature at which dissolution of the metallic diffusion barrier layer into the soldering composition occurs; and wherein, subsequent to the soldering, the metallic diffusion barrier layer remains contiguous such that no direct contact occurs between semiconductor materials of the semiconductor laser chip and the solder composition, such that no direct path exists by which constituents of any of the semiconductor laser chip , the solder composition, and the carrier mounting diffuse across the metallic diffusion barrier layer. forming a first contact surface of a semiconductor single-frequency laser chip for a tunable laser-based trace gas analyzer, especially for a tunable diode laser absorption spectrometer, to a target surface roughness, the target surface roughness being less than 100·10 -10 m rms, wherein a metallic diffusion barrier layer is applied to the first contact surface ; applying a metallization layer comprising 600·10 -10 m of titanium to the first contact surface prior to applying the metallic diffusion barrier layer; applying the metallic diffusion barrier layer to the titanium layer, wherein the metallic diffusion barrier layer includes multiple layers of differing materials, wherein a first metallic diffusion barrier layer comprises 1200·10 -10 m thickness of platinum; applying a solder preparation layer comprising approximately 2000·10 -10 m to 5000·10 -10 m thickness of gold to the metallic diffusion barrier layer subsequent to applying the metallic diffusion barrier layer and prior a soldering; soldering the semiconductor laser chip along the first contact surface to a carrier mounting using a solder composition , the soldering comprising melting the soldering composition by heating the soldering composition to less than a threshold temperature at which dissolution of the metallic diffusion barrier layer into the soldering composition occurs; and wherein, subsequent to the soldering, the metallic diffusion barrier layer remains contiguous such that no direct contact occurs between semiconductor materials of the semiconductor laser chip and the solder composition, such that no direct path exists by which constituents of any of the semiconductor laser chip , the solder composition, and the carrier mounting diffuse across the metallic diffusion barrier layer. <EOS>