Dietrich Martin

New solutions to realize complex optical systems by a combination of diffractive and refractive optical components

Diffractive optical elements (DOEs) have a great potential in the complete or partial substitution of refractive or reflective optical elements in imaging systems. The greater design flexibility compared to an all-refractive/reflective solution allows a more convenient realization of the optical systems and additionally opens up new possibilities for optimizing the performance or compactness. To demonstrate the opportunities of the hybrid optical concept we discuss different imaging systems for various applications. We present the lens design of a hybrid microscope objective which is especially applicable for wafer inspection technologies. Meeting the requirements for such a system used in the deep-UV regime (248 nm) is very challenging. The short wavelength limits the material selection and demands cement free optical groups. The additional requirement of an autofocus system, working at a wavelength in the near infrared region, is fulfilled by the special combination of two selected and adjusted DOEs. Furthermore, we discuss the opportunities of the hybrid concept c of a slit lamp used for ophthalmologic examinations. The DOEs are the basic elements of this hybrid concept. We demonstrate that holographic lithography is an appropriate technology to realize a wide variety of elements with different profile geometries. We address in particular the additional possibilities of an UV-laser system as an exposure tool. Additionally to the high spatial frequencies, the 266 nm exposure wavelength allows the use of novel photo resists with advantageous development behavior.

Advanced Optical Components

This chapter describes a selection of advanced optical components including the underlying physical principles, production techniques and already existing or possible future applications.

Subwavelength-resolution fluorescent correlation spectroscopy using a solid immersion lens

In this paper we present recent spectroscopic studies using a Solid Immersion Lens for Fluorescent Correlation Spectroscopy measurements. We compare the performance of the Solid Immersion Lens confocal microscope built-up in our group to the performance of a conventional confocal microscope used for FCS. The novelty of the new SIL-FCS microscope is a system containing a conventional objective (NA = 0.6) combined with a Solid Immersion Lens used for single molecule experiment. Important parameters for single molecule experiments such as collection efficiency and excitation field confinement are investigated for different modes of the SIL objective system.