An improved stepped etalon comprises a transparent body having a stepped surface. Adjacent step lands are separated from each other by a transition region which includes a curved, waved, or otherwise varied step wall such that the average height of the stepped surface does not change abruptly in the transition region from the height of one land to another, but instead varies gradually according to the particular shape of the step wall. In an alternative embodiment, the step transition is formed using a grey-scale or half-tone patterning in which the average height gradually varies across the transition region. The non-planar transition region reduces the amount of coherent interference caused by the step transition thereby reducing the dead spot behind the step transition portions where interference prevents accurate measurements of light transmission from being made.
The specification describes stepped etalon structures and techniques for their fabrication. The preferred etalon material is LiCaAlF.sub.6, which is not efficiently processed using reactive ion etching. The approach of the invention is to produce the steps on the etalon by depositing a blanket layer of step material that is effectively etched by RIE, masking a portion of the step material, and etching the masked blanket layer using the LiCaAlF.sub.6 substrate as an etch stop. These process steps may be repeated to form multiple steps on the etalon. Etalon structures with steps on both major surfaces are described, as well as etalon structures with steps having differing areas. In the latter case a difference in amplitude in the output signal from a single detector can be used to identify the step that is resonating.
A laser employing a tapered, thin film interference filter as a tuning element. Tapered, thin film interference filters employing dielectric layers are disclosed for use in tuning lasers. Methods of tuning a laser by adjustably positioning a tapered thin film interference filter are disclosed. Also included are a method for tuning a laser to account for thermal wavelength drift, a method of mounting an etalon in a substantially stress free manner, and a mount therefor.
A method of fabricating a plurality of composite optical assemblies is disclosed. Each optical assembly includes a first optical element and a second optical element. The method includes the steps of providing a first composite substrate that may be divided into a plurality of first optical elements and forming on an exposed surface of the first composite substrate a second composite substrate that may be divided into a plurality of second optical elements, the first and second composite substrates providing a composite structure.
A method of fabricating a plurality of composite optical assemblies is disclosed. Each optical assembly includes a first optical element and a second optical element. The method includes the steps of providing a first composite substrate that may be divided into a plurality of first optical elements and forming on an exposed surface of the first composite substrate a second composite substrate that may be divided into a plurality of second optical elements, the first and second composite substrates providing a composite structure.
The present invention provides an apparatus for mechanically stabilizing tunable lasers by mechanically grounding laser components. Lasers stabilized using mechanical grounding of the laser components exhibit phase synchronous tuning, reduced mode hop and increased wavelength stability across the entire tuning range. Additionally, lasers stabilized using mechanical grounding exhibit improved resistance to thermal and physical shock. The robust compact design of mechanically grounded lasers makes them suitable for a broad range of applications including optical signal generators and optical multimeters.
