Research On The Fabrication And The Optical Properties Of Integrative Bionic Optical Compound Eyes

The compound eyes of the insects in nature, such as the eyes of the fly, are multi-aperture optical detection systems as well as real time image processing and analysis systems that exist naturally in the world. Due to their curve surface, the compound eyes of the insects have the advantages of wild field of view and highly sensitivities to the moving objects. Not only that, the physiological structure of the compound eye are so ingenious that they also have the virtues of light weight and small volume. Therefore, the natural compound eyes have been the best model for fabricating the micro opto-electronic sensor, the micro opto-electronic detector, and the micro opto-electronic imaging system. Many researchers, including military scientist and medical scientist, have begun intense researching work on simulating the physiological structure and the physiological features of the compound eyes. At present, bionic compound eyes are often coupled by independent elements such as micro lens array and hole array. Of course, the precision of coupling is of high standards and high demanding. In order to reduce the volume of the bionic compound eye opto-electronic system, lower the difficult of coupling, we propose a physical model of integrative bionic compound eye and carry out relative research work on its optical properties, fabrication technology, application etc. The ommatidium unit of the proposed integrative bionic optical compound eyes which can be fabricated all at once in a single substrate, includes a micro lens array, a crystal cone and a cylindrical waveguide which are connected one by one. The contributions of this paper mainly include:Firstly, the physical model of the integrative bionic compound eye is proposed and the corresponding physical structure is constructed and described in detail. The ray matrix method is proposed to analysis the optical properties of the integrative bionic optical compound eyes, and the ray matrix of the integrative bionic compound eyes is deduced. The principle points as well as the transmission of Gauss beam in the integrative bionic compound eye are also analyzed. The ray matrix and the principle points of the integrative bionic compound eye are related tightly with the length of the cylinder waveguide part. Difference length of the cylinder waveguide will lead to different position of the principle point. Ray trace method is used to simulate the integrative bionic optical ommatidium and the image properties of the integrative compound eye.The finite-difference time-domain method is employed to simulate the self-focusing effect in nonlinear optical polymer, and it verifies the feasibility of fabricating integrative bionic compound eyes with the self-focusing effect in nonlinear optical polymer. Due to the quantization of the digital gray mask, it is proposed in this paper that the finite-difference time-domain method is used to simulate the self-focusing effect in nonlinear optical polymer which diffraction profile. Hence, the potopolymerization process in the plane film, the thin film with a micro lens, the film with diffractive micro lens quantized uniformly according to basal radius, and the film with diffractive micro lens quantized uniformly according to height are simulated. It is concluded from the simulated results that the self-focus effect resulted from the refractive index change can be used to fabricate the integrative bionic optical compound eyes. The simulation results of the film with micro lens and the film with diffractive micro lens quantized equally according to basal radius are similar, and the structures of the self-written waveguide approach the physical model of the integrative optical bionic compound eyes most.The technique process of the fabrication of the integrative bionic compound eyes is described in detail in this paper. Both the traditional chrome mask and the newly digital gray-tone mask are used in the lithographic process. It is proposed in this paper that curve substrate with suitable radius can be used to support the fabrication of curved integrative bionic compound eyes. The profile and the optical properties of the integrative bionic compound eye are measured and tested. The point spread function of the integrative bionic compound eyes is deduced theoretically by using of Fourier optics, and the simulation results of the point spread function agree with the test results.The applications of the integrative optical bionic compound eyes integrating with image sensor are also analyzed and discussed in this paper. The transmission of Gauss beam in the integrative bionic compound eye is also analyzed by using the ABCD law. Integrative optical bionic compound eyes are designed according to the sizes of two different commercial image sensors. The coupling efficiency between the semiconductor laser and the single mode fiber with the integrative bionic compound eye is also analyzed, and it is drawn that, to some extent, the length of the cylinder waveguide has some influence on the coupling efficiency.