OptoFluidic Adaptive Optics (OFAO)

• Applicant: Professor Dr. Caglar Ataman
• Subject Area: Microsystems ; Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 274458620

OptoFluidic Adaptive Optics (OFAO) envisions an unprecedented refractive adaptive optics system featuring a reconfigurable freeform membrane as the spatial phase modulator. Employed primarily in ground-based telescopes for atmospheric turbulence compensation, adaptive optics (AO) has long proven to be a costly yet powerful enabler of diffraction limited imaging through turbulent media. A plethora of life science microscopy methods both in confocal and full-field modalities have also adapted AO in recent years to enhance resolution as well as contrast in deep tissue imaging. Despite very promising results, widespread acceptance of AO is impeded primarily by the excessive cost. All practical AO systems share the same basic architecture of a reflective deformable mirror and a wavefront sensor combined in an intricate yet expensive optical arrangement. We propose a completely new approach to adaptive optics, which has the potential to significantly expand the application area of AO. To achieve this goal, OFAO will be active in the following topics:- Adaptive refractive surfaces capable of arbitrary wavefront correction: A cavity filled with an optical liquid and sealed by an elastic polymer constitutes the basic arrangement that OFAO will use. Using ITO, an electrically active yet optically transparent layer of many electrodes can deform the membrane in the desired shape; given the polymer membrane is conductive. An alternative approach is to use insulating membrane material and use an ionic liquid as the optical liquid. - Sensorless wavefront estimation using the information inherent in the image: Both for confocal and full-field microscopy, there now exist efficient algorithms that use the image plane information to estimate the wavefront distortion. OFAO will capitalize on these methods to eliminate the wavefront sensor and attain a fully in-line AO system compatible for majority of life science microscopy methods.- Control algorithms and electronics: For life-sciences, dynamic real-time imaging is as crucial as the imaging quality; therefore performing wavefront correction at a speed comparable to conventional AO systems is another major goal of OFAO. The challenge here is to translate the computed wavefront distortion into mechanical membrane profile, which will be addressed by both a software interface and high voltage driving electronics. OFAOs refractive adaptive optics system will not only simplify AO for life science microscopy, but also unravel new opportunities through miniaturization. The OFAO approach offers an ideal solution by bringing AO down to the objective level. Coupled with a software-based wavefront estimation algorithm and an external driving box connected to it via a simple interface, such an AO objective would elevate a conventional microscope to an AO microscope, capable of correcting sample-induced, environmental and illumination-related wavefront errors.

• DFG Programme: Research Grants