光分碼多重擷取 (Optical Code Division Multiple Access, OCDMA)類似射頻分碼多重擷取(RF-CDMA)技術，在光纖擷取網路，每一使用者設定一個獨特編碼， 在接收端必需要在眾多使用者之中對抗其他干擾而只撿測到自己的編碼。
光分碼多重擷取系統分為時域(time domain)、空域(spatial domain)及波域(wavelength domain)，這些編碼稱為一維光分碼多重擷取(1-D OCDMA)，一維光分碼多重擷取由於效率及性能不佳因而有二維光分碼多重擷取(2-D OCDMA)的發展。
二維光分碼多重擷取分為：1). 時域/空域(time/spatial) 2). 空域/波域(spatial/wavelength) 3). 波域/時域(wavelength/time)。這些二維光編碼比一維光編碼有較多的編碼數量，而且二維光編碼設計成單一碰撞碼(one hit or one-coincidence code)則自相關性零異相(zero out-of -phase autocorrelation)，互相關性只有一個碰撞(the cross-correlation equal to one)的特性，如此可以降低多重擷取干擾(multiple access interference, MAI)，而本論文所提出的單一碰撞波域/時域編碼可以應用在非同調光纖網路(incoherent OCDMA networks) 具有較多有效使用者、具有較高頻譜效率、以及具有最小碰撞率的特性。
在這本論文提出了二種波域/時域光分碼多重擷取的編/解碼系統，一個是合併最大長度碼/質數碼(merged-M/prime code)，另一個是延長二次餘碼/光正交碼(extend quadratic congruence/optical orthogonal code,EQC/OOC) ，然後應用布雷格光纖光柵(Fiber Bragg Gratings, FBG) 以及陣列波導光柵路由器(Arrayed- Waveguide Grating, AWG)來設計此兩種光分碼多重擷取的編/解碼器系統。
在系統分析上提出兩種方法：1. 二項式機率分配(the Binomial probability distribution approach) 2. 高斯分配(Gaussian approach)來分析其誤碼率(Bit Error Rate, BER)，在雜訊分析上亦考慮APD (avalanche photodiode)雜訊。
因此，所提出的系統在非同調光纖網路，證實擁有較大的編碼數而有較多的有效使用者，並且系統的實現比起其他系統更簡化更經濟。

The OCDMA (Optical Code Division Multiple Access) system is similar to the RF CDMA system, each user is assigned a unique signature code with which to access the network, and the receiver must be capable of detecting this signature sequence against the background of interference from other users.
The OCDMA coding techniques can be divided into: (1). Coding in the time domain such as direct sequence; (2). Coding in the wavelength domain using either coherent (spectral phase) or incoherent (spectral amplitude) approach; (3). Coding in the spatial domain with the M-matrix codes. These OCDMA codes are called one-dimensional (1-D) codes. 1-D OCDMA is limited by inefficiency and poor system performance. In order to overcome the drawbacks of 1-D OCDMA, two-dimensional (2-D) codes are developed
The 2-D OCDMA coding schemes can be classified into three kinds: (1). Temporal/Spatial (T/S) coding; (2).Spatial/Wavelength (S/W) coding; (3). Wavelength/Time (W/T) coding. These 2-D OCDMA codes have more cardinality than 1-D OCDMA, furthermore, one-coincidence 2-D OCDMA has zero out-of-phase autocorrelation and the cross-correlation equal to one, which can reduces the MAI. The proposed one-coincidence wavelength-hopping/time-spreading (W/T) code is suited to incoherent OCDMA networks that have large cardinalities, high spectral efficiencies, and minimal cross correlation values.
In this dissertation, we propose two types of one-coincidence W/T coding schemes. One is the merged-M/prime code and other is the EQC/OOC. Then we design encoder/decoder based on fiber Bragg gratings (FBG) and the cyclic property of Arrayed-Waveguide Grating (AWG) router.
The performance of the OCDMA system is confirmed by two methods: 1. the Binomial probability distribution approach. 2. Gaussian approach. The APD (avalanche photodiode) noise is also considered in the system.
Thus these 2-D OCDMA systems have larger capacity and then have larger number of active users to access simultaneously in the incoherent OCDMA system, moreover, the design of networks which we proposed can make the whole architecture simpler and more economical than other types of W/T OCDMA.

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