Adjustment method, particularly a laser adjustment method, and an actuator suitable for the same
View Patent ↗The invention relates to an adjustment method, especially for the adjustment of optical or fiber optical components, whereby a partial region of an actuator is locally heated in such a defined manner that compressive stresses are created therein as a result of the restricted thermal expansion of said heated partial region, caused by at least one other partial region of the actuator. If the yielding point σ of the material of the partial region is exceeded, said compressive stresses lead to the plastic compression of the heated partial region. Furthermore, said heated partial region is contracted during cooling and leads to a defined modification of the geometry of the actuator following the cooling process. Tensile stresses are created as a result of a restriction of said contraction by means of at least one other partial region in the previously heated partial region, and compressive stresses are frozen in the at least one other region. During the adjustment process, essential regions of the actuator, in which the tensile stresses or compressive stresses are frozen after cooling, are brought to a critical temperature in relation to the operating temperature of the actuator, at least until flow processes of the material are ended at the critical temperature.
1. An optical subassembly and adjustment system comprising:
an actuator;
an optical component physically joined to the actuator;
means for heating at least a portion of the actuator to a critical temperature determined relative to a usage temperature range of the actuator;
means for locally heating a selected subregion of the at least a portion of the actuator brought to the critical temperature such that compressive stresses arise in the selected subregion, which, upon reaching a yield point of the material of the selected subregion, results in plastic deformation of the selected subregion; and
means for cooling the selected subregion, such that the selected subregion is shortened, resulting in a defined geometric change of the actuator and corresponding displacement of the optical component to a predetermined position, wherein the actuator comprises:
a base;
an adjustment region that moves in response to the means for locally heating and the means for cooling; and
a pair of double bridges that connect the base and the adjustment region, wherein the selected subregion is included in one of the bridges of the pair of double bridges.
2. The optical subassembly and adjustment system of claim 1 , wherein at least the selected subregion of the actuator is formed from a material having a yield point that assumes a minimum value within the entire usage temperature range essentially at room temperature.
3. The optical subassembly and adjustment system of claim 1 , wherein the means for locally heating the selected subregion comprises a laser.
4. The optical subassembly and adjustment system of claim 3 , wherein the laser comprises an Nd:YAG laser.
5. The optical subassembly and adjustment system of claim 3 , wherein the laser comprises a diode laser.
6. The optical subassembly and adjustment system of claim 1 , wherein the critical temperature is selected to be essentially the temperature within the usage temperature range at which the minimum yield point of the material is attained.
7. The optical subassembly and adjustment system of claim 1 , wherein the material of the selected subregion has a yield point that drops monotonically within the usage temperature range.
8. The optical subassembly and adjustment system of claim 7 , wherein the critical temperature is selected to be essentially the temperature at an upper limit of the usage temperature range.
9. The optical subassembly and adjustment system of claim 1 , the means for locally heating and the means for cooling causing tensile stresses to arise in a first subregion of the actuator and, in a second region of the actuator, causing the compressive stresses to be frozen.
10. The optical subassembly and adjustment system of claim 1 , the means for heating the at least a portion of the actuator to the critical temperature including an infrared radiation source.
11. The optical subassembly and adjustment system of claim 1 , the means for heating the at least a portion of the actuator to the critical temperature including a laser.
12. The optical subassembly and adjustment system of claim 11 , the laser being configured to scan a laser beam over the at least a portion of the actuator to bring the at least a portion of the actuator to the critical temperature.
13. The optical subassembly and adjustment system of claim 1 , the means for heating the at least a portion of the actuator to the critical temperature being configured to bring a subassembly including the actuator to the critical temperature.