In optical systems it is often desirable to have an optical element, such as a mirror, prism, or lens, mounted so as to be precisely positionable. Moreover, it is often required that both considerable range in adjustment and precision in adjustment be provided. These two goals, when presented to a mounting designer trying to design a mounting that is also simple and low-cost, are inherently at odds with each other. Typically the provision of considerable range of motion can be at the expense of precision in placement and retention of the optical element at a particular place and directional attitude.
Moreover, it is often desirable to provide adjustment in as many planes and rotational axes as possible. Again this design goal typically is at odds with the goals of providing precision and stability over time and condition changes, as well as making the mount simple and less costly.
The inventors have recognized that it is desirable to provide a stable optical element mount that is translationally adjustable as to position in the x, y and z orthogonal directions and is rotationally adjustable as to tilt in at least 2 of the x, y, and z orthogonal rotational axes. Briefly, and in general terms, the invention accordingly provides an optical mirror mount comprising an outer body and a positionable inner mount body adjustable with respect to the outer body in the x, y and z directions, and at least two of the x, y and z rotational axes; the inner positionable mount body being configured to carry an optical element.
In a more detailed aspect, the outer body can define an opening for enabling the optical element to be accessible to a photonic stream, and the inner positionable mount body can be carried by the outer body via fine adjustment elements and elastic retaining elements; the latter providing stabilizing restoring forces biasing the inner positionable mount body against the fine adjustment elements.
Further features and advantages of the invention will be appreciated with reference to the following detailed description of example embodiment(s), taken in conjunction with the accompanying drawing figures illustrating same, wherein:
With reference to
The system 10 can include manual or automated means 22 for adjusting the directional attitude of the non-linear crystal 20. For example the mount 14 can be adjusted as described below, and/or further adjustment can be interposed between the mount and the crystal, so that once the lattice of the crystal has been precisely aligned using the mount's adjustment capability, further deflection of a controlled nature can be done to move the element into a selected attitude difference with respect to the photonic stream 12.
With reference to
For ease of assembly, the outer body 32 can be formed in two parts. In the illustrated example these are a holder 50 and a cover 52. The cover includes an opening 53 to accommodate light access to the optical element 38 in the illustrated embodiment, or for the inner positionable body 34 to pass through if the optical element is carried outside the outer body (not shown in the figure, but e.g. such as is shown in
In the illustrated embodiment including a holder 50 and cover 52, threaded fasteners 54 hold the cover to the holder. This is done after other structure shown has been placed inside. With the fastening of the cover to the holder, they work together to form the outer body 32 of the mount 14 of the illustrated embodiment.
The inner postitionable member 34 has a central portion 56 and three outwardly extending arms 58, 59, and 60. In the illustrated embodiment one of said arms 60 is aligned with the Y-axis. The others (58, 59) are each disposed at an oblique angle to one of the X & Y axes, e.g., at an angle between 15 and 75 degrees, such as at 45 degrees. The central portion has a horizontal bearing surface 62 and a vertical bearing surface 64 and a bearing surface 66 disposed obliquely to the previously mentioned vertical and horizontal surfaces. In the illustrated embodiment the obliquely disposed surface 66 is oriented at an angle inclined between 15 and 75 degrees, such as 45 degrees, from each of the vertical and horizontal bearing surfaces, (and the X & Y axes).
These horizontal and vertical bearing surfaces 62, 64 are biased against horizontal and vertical position fine adjustment elements, which in the example are threaded set screws 68, 70 respectively, which turn trough fine-threaded openings 72, 74 respectively, in the holder 50 of the outer body 32. This biasing is accomplished by means of an X/Y position biasing spring 76, which bears against the obliquely disposed bearing surface 66. The spring tension is adjustable by a threaded setscrew 78, which is threadably received in the holder element of the outer body. This arrangement allows adjustment in position of the inner positionable member up and down, and right and left, in a Z-plane (orthogonal to the Z axis, which in the figures is parallel to or coaxial with the optical axis 40, as mentioned) and along X and Y axes (77, 79, respectively) as shown.
In one embodiment, the inner tips 80, 82 of the fine adjustment element screws are given a rounded or domed configuration. This reduces inter-adjustment cross talk, i.e. unintentional movement in one direction or about one axis when position or tilt with respect to another is being adjusted.
The three outwardly extending arms 58, 59, 60 of the inner positionable body 34 are used in tilting adjustments, and in positioning of the inner positionable body in the Z direction, i.e., along the Z axis (optical axis) 40 in the figures. They are each biased against Z/tilt fine adjustment element screws 84, 85, 86, respectively, by Z/tilt biasing springs 88, 89, 90 respectively. Again, tip portions 92, 94, 96 of these fine adjustment elements can also be given a rounded/domed configuration in one embodiment, again to reduce adjustment cross talk. All of these fine adjustment screw elements are threadably received through the holder portion 50 of the outer body 32 by finely threaded openings found therein (hidden behind other structure in the view). The biasing springs 88, 89, 90 are retained against the arms by the cover 52 of the outer body 32 discussed above.
It will be appreciated that by turning each of the Z/tilt fine adjustment screws 84, 85, 86 in the same direction of rotation the Z position of the optical element 38 carried by the inner positionable body 34 can be adjusted. By turning them differentially with respect to each other, the tilt of the optical element with respect to the X, Y and Z-axes 77, 79, 40, respectively, can be adjusted. These adjustment screw elements adjust by rotation about, and adjust rotational position with respect to, the X and Y axes in the figure. In one embodiment, such as that illustrated, the tilt of the optical element with respect to the Z-axis 40 can be adjusted by rotating it with respect to the inner positionable body 34. In the illustrated embodiment this can be accommodated by a round shape aspect of the optical element and the receptacle 36 that receives it. In one embodiment an elastomeric O-ring 93 in a groove in the receptacle firmly holds the optical element 38 preventing unintentional movement, but can accommodate rough adjustment along the Z-axis and rotation about the Z-axis. In another embodiment a further intermediate element (not shown) can be provided which is adjustably rotatably carried by the inner positionable body and which in turn carries the optical element, providing rotational adjustability about the Z-axis. As will be appreciated, most optical elements are essentially symmetrical about the Z (optical) axis and thus generally do not require adjustment in this respect. However, this feature can be provided as mentioned herein in one example embodiment if this additional functionality is desired.
With reference to
With reference to
It will be appreciated that an optical element mount 14 in accordance with the invention can provide a solution to the problems of providing precision of adjustment with a relatively large range of adjustment in X, Y, and Z directions and at least two of 3 rotational directions in a mount of relatively simple (i.e. less costly) configuration.
While one or more example embodiment(s) have been described herein with particularity, it will be appreciated that numerous changes can be made within the purview of ordinary skill in the art, and without the exercise of inventive faculty. It is not intended that the scope of the invention be limited by the example(s) set forth herein.