Study On The Effective Distance Evaluation Of The Quantum Imaging

Being the conclusion of Einstein-Podolsky-Rosen, nonlocal behavior of two entangled photon has been widely admitted. Quantum imaging, derived from this nonlocal character, has many properties superior to other classical imaging techniques, attracting much attention. However, it has been proved, in recent years, that quantum imaging can also be performed with a thermal source, both theoretically and experimentally. Thermal source is easily obtainable, so, compared with correlated imaging with an entangled source, correlated imaging with a thermal source has more broad prospects. So the topic of ghost imaging, particularly the quantum imaging with thermal light, in recent years as a hot topic, has aroused the interest of all. which make correlated imaging more widely used in other fields.This paper focuses on the properties of ghost imaging with thermal light, and makes evaluation about the effective distance range. The main content includes:1. The paper briefly reviews the origin and the history of correlated imaging. Then, the imaging model of pseudo-thermal light is analyzed theoretically, and the concept of the pseudo-thermal light is introduced, and the coherence theory of it is also analyzed.2. The scheme of second-order correlated imaging with thermal light is researched, from which the expressin of "ghost imaging"--the second-order correlation function is derived. Further more, there is no difficult to study the influences of the source, optical system and the object imaged on the imaging quality such as the resolution, visibility and signal-to-noise (SNR).3. The relationship of the resolution, visibility and SNR are investigated by using software Mathematic respectively, which are discussed in detail by numerical simulations, and take the three factors into consideration to get the effective distance range. 4. The verification for the theoretical study is done. The pseudo-thermal light is produced experimentally, when the distance between the object and CCD is varying, the best imaging appears. So far, we have proved the theory in practice.It is shown that the imaging quality of the quantum imaging of the pseudo-thermal light can be evaluated by resolution, visibility and SNR. The relation curves between the three parameters and the effective distance are obtained. Then the intersection of the distance range can also be got. The effective distance of the imaging system can be evaluated finally. The quantum imaging of pseudo-thermal light, compared with classical imaging, has better resolution, SNR and visibility, with high clarity and far distance.