## 1 Introduction  
Building an optical communication network using two optical sources, despite the difference in their optical wave behavior, may result in the construction of a network that can provide reliable services at a reasonable cost. Recent research has focused on the latest technology that can provide quality of service (QoS) at an affordable cost. For this reason, bandwidth-starving applications increase exponentially. To provide increased-bandwidth connections in both metropolitan area networks (MANs) and local area networks (LANs), the optical communication system is of great importance, where a large number of users in a comparatively small area occasionally need to connect with other users in the network at data rates of Gbit/s [1; 2]. The most important necessity of LAN is to permit users to have easy and fast network access. The optical code division multiple access (OCDMA) technique acts as a powerful candidate for LANs. OCDMA is a multi-access system developed and designed in such a way that a distinct code is allocated to each user. The user identifies the matched code to identify the required information from the concurrent users [1; 2]. The spectral amplitude coding (SAC) OCDMA system has gained popularity since multiple access interference (MAI) was suppressed using spectral coding [3]. However, as long as the number of subscribers increases, the MAI increases, resulting in increased bit error rate (BER) values which eventually limits the network capacity. There are a large number of codes available for the SAC- OCDMA system, and the interested reader may refer to references [4; 5; 6; 7; 8; 9; 10; 11]. The SAC- OCDMA code system uses low-priced broadband incoherent sources such as amplified spontaneous emission (ASE) and light-emitting diodes (LEDs). These sources are matched with SAC- OCDMA operation by nature, and it must be realistic when implemented commercially. Signature code patterns can be easily achieved by chipping the frequency spectrum via different kinds of optical filters. Additionally, using LED sources has advantages such as a simple and easy implementation and large bandwidth [12]. However, when high transmission rates are desired, the use of LED sources imposes bandwidth limitation constraints on the system and reduces spectrum efficiency because their intensity noise limits system performance [13]. Experimental and simulation work published on SAC-based systems mostly employs incoherent broadband sources. The main issue with such sources is that they provide low data rates when long-distance communication is involved due to intensity noise impact [14]. Thus, coherent light sources must be incorporated in place of LEDs for long-distance communication due to their increased transmission capabilities in terms of data transmission rates and fiber distance compared to conventional optical sources [15]. At the same time, the drawback of such a system is that one laser for each code weight per user is required, eventually affecting the cost of the system and increasing complexity [16]. Moreover, the choice of a laser diode over an LED as a light source in a fiber optical medium depends on a number of factors such as the target application, related system performance, and reliability requirements of the overall solution being designed [17]. The first-time application of a multi-laser source for the OCDMA system is introduced and its performance comparison is made with two different optical sources (a broadband erbium-doped fiber source and a multi-array source) in terms of BER and data rates [18]. The multi-array source outperformed the incoherent source for the chosen design parameters. The use of a multi-array laser source in the SAC system is introduced by considering different strategies such as coherent sources and multi-array laser sources with forwarding error correction (FEC). SAC system performance is checked in terms of transmission capacity and cost. Further, performance comparison and trade-off are made among these techniques [19].