First-order gain-coupled distributed feedback lasers have been fabricated in the (Ga,In)As/(Al,GA)As material system by maskless patterning with focused ion beam implantation. The laser devices are operating at 77 K and room temperature at emission wavelengths between 1.0 and 0.7 mu m. The structures obtained are thermally stable up to annealing temperatures of 800 degrees C. A full in situ processing of gain-coupled distributed feedback laser structures was for the first time successfully demonstrated. This process includes molecular beam epitaxy, grating patterning by focused ion beam and epitaxial overgrowth. All processed lasers show single mode emission at all operating conditions as expected for gain-coupled lasers.