單光子的偵測

Detection of Single Photon

洪禾羢(He-Rong Hong)

指導教授 ： 周志隆

中原大學/理學院/應用物理研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700543

摘要

摘要
目前國防通訊或是重大交易上面或者是想保護自己的資料不被入侵盜取所採用的密碼保護，都是以傳統的密碼來保密，這是不安全的。因為所謂的傳統密碼是以0或1的程式語言來傳輸，但是傳統密碼不安全的地方是在於傳輸的過程中，傳統密碼如果以光來傳送密碼，0和1的判讀是以光強度來分別，所以說竊聽者盜走資訊之後再把光資訊放回去，而我們偵測到的光資訊會是原本的光資訊，因此我們並不會知道在通訊過程中被竊聽了。所以在秘密通訊上是非常不安全的。如果在通訊過程中，有人竊聽的話，資訊上就會改變原來的狀態，我們就可以輕易的查覺是否有被竊聽了。量子密碼跟傳統密碼的差別就在這！量子密碼利用量子物理的特性，如果量子態被測量時，量子態就會改變原來的狀態，所以說如果資訊遭到竊聽(測量)，就會改變原來的狀態。因此量子密碼可以說是非常的安全。然而要達到量子密碼的要求，傳輸的資訊必須是量子態，那就是單光子。以單光子來傳送訊息。

量子密碼理論上可以說是非常的安全，所以說量子密碼是必會取代傳統密碼，讓通訊更加的安全，因此本文介紹量子密碼的理論和實驗架構為基礎，藉由本文來了解量子密碼的理論，如何產生量子密碼和傳遞量子密碼鑰匙(單光子)。主要是了解SPAD和量子點的偵測系統如何去偵測單光子和偵測的系統原理和機制。在單光子產生器的部分，現階段所使用的光源為Faint Laser Pulse光源，比較Faint Laser Pulse和新的單光子產生技術(量子點單光子源)的差別在哪裡。

關鍵字

庫倫障礙 ； 量子點 ； 電子電洞對

並列摘要

Abstract
National defense communication or great trade is it protect one's own materials invade cryptography adopted to steal protect to want at present, all keeping secret with the traditional cryptography, this is unsafe. Because so-called traditional cryptography 0 or 1 procedure language. That the traditional cryptography unsafe place lie in the course transmitted, if traditional cryptography conveys the cryptography with the light, the interpretation of 0 and 1 is to part with luminous intensity, so say the eavesdropper and then sets mere information free back after stealing information, and we detect the mere information examined will be the original mere information, so we will not know that has been eavesdropped in the course of communication. So it is very unsafe on the secret communication. If in the course of communication, if someone eavesdropped, will change the original state on information, we can be conscious easily whether to eavesdrop or not. The quantum cryptography follows the difference of traditional cryptography just here! Quantum cryptography utilize quantum physics characteristic, if the quantum state be measurement, the quantum state will change the original state, so say if information is eavesdropped (measurement),the original state will be changed. So the quantum cryptography is very secure and safe. The information of quantum cryptography transmitted must be a quantum state that is single photon.

Security which say to be extraordinary in theory of quantum cryptography, say quantum cryptography must replace traditional cryptography, let communication further safe, so based on this introduces the theory of the quantum cryptography and experiment structure, is it find out about theory, quantum of cryptography to come by this text, how produce quantum cryptography and transmit quantum cryptography key (single photon). To understand SPAD and quantum dots how is it detect single photon and detect principle and mechanism. In the part of the single photon generator, light source that use Faint Laser Pulse light source the present stage, compare what are the Faint Laser Pulse and new single photon produce technology (quantum dots single photon source) difference.

並列關鍵字

Electron-Hole Pair ； Quantum Dots ； Coulomb Blockade

參考文獻

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