Thermally tunable laser and method for fabricating such laser

A thermally tunable laser comprising:a substrate having an upper side and a lower side;a laser resonator for producing a laser emission having a horizontal direction, wherein the laser resonator is arranged at the upper side of the substrate, wherein the laser resonator comprises a gain section for producing light for the laser emission, and wherein the laser resonator comprises a tuning section for tuning a wavelength of the laser emission, wherein the tuning section is arranged at an horizontal end of the gain section;a heating arrangement for heating the tuning section;a heat sink arrangement for dissipating a heat flow from the laser resonator to the heat sink arrangement, wherein the heat sink arrangement is arranged at the lower side of the substrate; anda hole arrangement for influencing the heat flow from the laser resonator to the heat sink arrangement, wherein the hole arrangement is arranged between the substrate and the heat sink arrangement, wherein one or more holes of the hole arrangement comprise at least one hole being arranged within a horizontal range of the tuning section, so that a thermal resistance between the tuning section and the heat sink arrangement is increased.