USAGE OF WAVELENGTH MULTIPLEXING FOR SUPER RESOLVED IMAGING AND SPATIAL DATA COMPRESSION.

In this chapter we present the usage of optical wavelength multiplexing configuration applied in order to encode spatial degrees of freedom and then to mix/compress the spatial data to allow its efficient transmission through a single mode fiber or through a low resolution (band limited) imaging system such as a microscope. After the transmission of the encoded data, one may decode the multiplexed spatial information and to recover the high resolution 2-D image. The wavelength multiplexing is realized either by the usage of diffractive optical elements (DOE) or by a metallic plate of sub-wavelength holes-array having spatially varying pitch distances. The diffraction of light through the DOE or the spatially varied pitch distances between holes directs different wavelengths to different spatial positions and by that performs the wavelengths based mapping/encoding of the space domain. The decoding of the spatially mixed/compressed data is obtained either by a decoding DOE that resembles the encoding element or by usage of a spectrometer. The proposed concept is validated experimentally for transmission of information over a single mode fiber and later on applied for an improved microscope configuration (imaging application) which is being either without an objective lens (but with a condenser lens) or a microscope configuration that is even becoming a fully lens-less in the case when we use the non periodic metallic plate of sub-wavelength holes.