Abstract: A high power laser source comprises a bar of laser diodes having a first coefficient of thermal expansion CTEbar on a submount having a second coefficient CTEsub and a cooler having a third coefficient CTEcool. The submount/cooler assembly shows an effective fourth coefficient CTEeff differing from CTEbar. This difference leads to a deformation of the crystal lattice of the lasers' active regions by mechanical stress. CTEeff is selected to be either lower than both CTEbar and CTEcool or is selected to be between CTEbar and CTEcool. The submount may either comprise layers of materials having different CTEs, e.g., a Cu layer of 10-40 ?m thickness and a Mo layer of 100-400 ?m thickness, or a single material with a varying CTEsub. Both result in a CTEsub varying across the submount's thickness.

Abstract: A high power laser source comprises a bar of laser diodes having a first coefficient of thermal expansion CTEbar on a submount having a second coefficient CTEsub and a cooler having a third coefficient CTEcool. The submount/cooler assembly shows an effective fourth coefficient CTEeff differing from CTEbar. This difference leads to a deformation of the crystal lattice of the lasers' active regions by mechanical stress. CTEeff is selected to be either lower than both CTEbar and CTEcool or is selected to be between CTEbar and CTEcool. The submount may either comprise layers of materials having different CTEs, e.g., a Cu layer of 10-40 ?m thickness and a Mo layer of 100-400 ?m thickness, or a single material with a varying CTEsub. Both result in a CTEsub varying across the submount's thickness.

Abstract: A high power laser source comprises at least a bar of laser diodes with a first coefficient of thermal expansion (CTEbar), a submount onto which said laser bar is affixed with a second coefficient of thermal expansion (CTEsub), and a cooler onto which said submount is affixed with a third coefficient of thermal expansion (CTEcool). The submount/cooling assembly exhibits an effective fourth coefficient of expansion (CTEeff). According to the invention, mechanical stress exerted to the laser bar improves reliability and optical performance. To effect this, CTEeff must differ from CTEbar, CTEeff?CTEbar. Preferably, CTEeff should differ by a predetermined amount from CTEbar. The difference is achieved in two ways: either by selecting CTEsub>CTEbar and CTEsub?CTEcool, or by selecting CTEsub<CTEbar and CTEsub<CTEcool. Thereby, all coefficients must be selected such that CTEeff differs from CTEbar: CTEeff?CTEbar, preferably by a percentage of 5% or by a predetermined amount of +/?3-4×10?7K?1.

Abstract: A high power laser source comprises a bar of laser diodes, a submount onto which said laser bar is affixed, and a cooler onto which said submount is affixed. The laser bar has a first coefficient of thermal expansion (CTEbar), the submount has a second coefficient of thermal expansion (CTEsub), and the cooler has a third coefficient of thermal expansion (CTEcool) the third coefficient (CTEcool) being higher than both said first coefficient (CTEbar) and said second coefficient (CTEsub). Contrary to the usual approach with a CTEsub matching the CTEbar, the second coefficient (CTEsub) is selected lower than both said first coefficient (CTEbar) and said third coefficient (CTEcool) according to the invention. A preferred range is CTEsub=k*CTEbar, with 0.4<k<0.9. The submount may consist of or comprise two or more layers of different materials having different CTEs, e.g.

Abstract: The present invention concerns an anti-reflection coating for semiconductor lasers, in particular a coating on the laser facet with advantageous properties resulting in improved reliability and reduced probability of specific breakdowns, especially so-called catastrophic optical damages (CODs). It is a quarter-wave coating with a predetermined reflectivity, preferably between 0 and 10% and consists of or comprises SiNx:H. It is preferably applied by a Plasma-Enhanced Chemical Vapor Deposition (PE-CVD) process whose process parameters are controlled such that a desired optical thickness and refractive index of the coating are achieved. The PE-CVD process may be controlled to result in an Si/N ratio between about 0.5 and 1.5 and/or to produce a coating of essentially amorphous SiNx:H whose density approaches the density of crystalline Si3N4.

Abstract: The present invention concerns an anti-reflection coating for semiconductor lasers, in particular a coating on the laser facet with advantageous properties resulting in improved reliability and reduced probability of specific breakdowns, especially so-called catastrophic optical damages (CODs). It is a quarter-wave coating with a predetermined reflectivity, preferably between 0 and 10% and consists of or comprises SiNx:H. It is preferably applied by a Plasma-Enhanced Chemical Vapor Deposition (PE-CVD) process whose process parameters are controlled such that a desired optical thickness and refractive index of the coating are achieved. The PE-CVD process may be controlled to result in an Si/N ratio between about 0.5 and 1.5 and/or to produce a coating of essentially amorphous SiNx:H whose density approaches the density of crystalline Si3N4.

Abstract: A semiconductor laser arranged to emit at a given wavelength has a light emitting facet carrying a phase-shifting anti-reflection coating, whose thickness is one quarter that of the given wavelength. Coupling at the light emitting facet is arranged to take place at the minimum of the standing wave.