Multi-actuator deformable optical mirror
Thorlabs
1020 (Kilo-DM) Actuator Model Available Through Boston Micromachines Corporation
3.5 µm Maximum Actuator Displacement
400 µm Center-to-Center Actuator Spacing and Low Inter-Actuator Coupling Results in High Spatial Resolution
Actuator Stroke with Zero Hysteresis
14 Bit Drive Electronics Yields Sub-Nanometer Repeatability
Compact Driver Electronics with Built-In High Voltage Power Supply Suitable for Benchtop or OEM Integration
Operating Wavelengths: 400 - 1100 nm for Al-Coated DM or 600 - 1100 nm for Au-Coated DM
Protective Window with 6° Wedge and Broadband Antireflection Coating (400 - 1100 nm)
Through our partnership with Boston Micromachines Corporation (BMC), Thorlabs is pleased to offer BMC's Mini-DM and Multi-DM micromachined deformable mirror systems for advanced optical control. To facility installation and setup, each package includes the deformable mirror, driver, and control software. These mirrors are capable of changing shape in order to correct a highly distorted incident wavefront (Refer to theTypes of Aberrations tab to learn more about the aberrations that a DM can correct). Micro-electro-mechanical (MEMS) deformable mirrors are currently the most widely used technology in wavefront shaping applications given their versatility, maturity of technology, and the high resolution wavefront correction that they afford.
These popular and versatile DMs, which are fabricated using polysilicon surface micromachining fabrication methods, offer sophisticated aberration compensation in easy-to-use packages. The mirror consists of a mirror membrane that is deformed by either 32 electrostatic actuators (i.e., a 6 x 6 actuator array with four inactive corner actuators in the case of the Mini-DM) or 140 electrostatic actuators (i.e., a 12 x 12 actuator array with four inactive corner actuators in the case of the Multi-DM), each of which can be individually controlled. These actuators provide 3.5 µm stroke over a compact area. In addition, the Kilo-DM with 1020 actuators (i.e. a 32 x 32 actuator array with four inactive corner actuators) is available through Boston Micromachines Corporation. The Kilo-DM deformable mirror actuators provide 1.5 µm stroke. Unlike piezoelectric mirrors, the electrostatic actuation used with BMC's mirrors ensures deformation without hysteresis.
The Mini-DM, Multi-DM, and Kilo-DM are available with either a gold- or aluminum-coated mirror. All three deformable mirror product lines have a protective 6o wedge in front of the mirror with a broadband AR coating for the 400-1100 nm range (Refer to the Graphs tab for coating curve information. Please contact tech support if you have an interest in a different coating range). Although the use of DMs in astronomy is well known, these miniature, precision wavefront control devices are also helping researchers to make breakthroughs in beam forming, microscopy, laser communication, and retinal imaging.
Muti-DM (140 Actuators) Choosing a DM for Your Application:
Ideally, the deformable mirror needs to assume a surface shape that is conjugate to the aberration profile in order to compensate for the aberrations present. However, the actual range of wavefronts that can be corrected by a particular deformable mirror is limited by the actuator stroke and resolution, the number and distribution of actuators, and the model used to determine the appropriate control signals for the DM; the first two are physical limitations of the deformable mirror itself, whereas the last one is a limitation of the control software utilized.
The actuator stroke is another term for the dynamic range (i.e., the maximum displacement) of the DM actuators and is typically measured in microns. Inadequate actuator stroke leads to poor performance and can prevent the convergence of the control loop.
The number of actuators determines the number of degrees of freedom that the mirror can correct for. Although many different actuator arrays have been proposed, including square, triangular, and hexagonal, most deformable mirrors are built with square actuator arrays, which are easy to position on a Cartesian coordinate system and map easily to the square detector arrays found on wavefront sensors. To fit the square array on a circular aperture, the corner actuators are often inactive.
