## 1 Introduction  
Recently, conventional lighting sources for general lighting applications have been replaced quickly by LED-based light sources. LED-based light sources have advantages to the conventional ones in terms of guaranteed longer life, lower power consumption, higher brightness, and less harmfulness for the environment [1, 2, 3, 4]. However, conventional lighting sources are still mainstream in the area of special lighting applications such as airports and seaports, because these special lighting applications require additional characteristics or special features of more uniform light distribution or higher lighting system reliability, and so on [5, 6, 7, 8, 9]. A seaport luminaire shall provide proper illumination to guide ships into port and to support workers in the port to maintain a high level of safety and visibility [10, 11, 12]. In the case of a conventional seaport luminaire, based on high-intensity discharge (HID) technology such as metal halide and high-pressure sodium lamps, due to glare, the eyestrain of port workers and navigators is at a considerable level [13]. As a result, safety accidents and other work efficiency deterioration are concerns. In order to improve this kind of situation, efforts are being made to solve the problem by installing reflectors and beam-blocking brackets in the luminaire. However, these kinds of solutions reduce the efficiency of the light source and subsequently increase the volume,weight, and price of the luminaire, too. The luminous flux of LED elements is constantly increasing, and precise light distribution control by optimal lens design is required for desired lighting performance even in lighting products using LEDs [14; 15; 16; 17]. The general radial light distribution curve induces the disability or discomfort of workers or pedestrians due to glare and uneven light distribution. It is possible to suppress glare and optical illusions through the realization of an optimal asymmetric light distribution with a high-power LED light source [18]. However, upon implementing a high-power LED light source, the heat dissipation problem of the corresponding lighting fixture is being raised as a key point, as it is inevitable to replace the LED lighting that replaces it with a conventional 500 W class luminaire in the seaport. In other words, as the output of the LED increases, the amount of heat generated increases, which affects the life and reliability of the LED [19; 20; 21; 22; 23]. Therefore, the heat generated from the LED chip is effectively removed using the metal heatsink to extend the life of the LED chip and increase the light efficiency. Thus, it is necessary to develop a lightweight and optimized high heat-dissipating structure for the seaport LED luminaire. In heat dissipation, it is necessary to implement optimal heat dissipation characteristics by appropriately utilizing the most effective conduction and convection. The key to the heat dissipation design of high-power LED port luminaires should be light weight, convenient maintenance, and no reduction in product life and light efficacy by heat dissipation. In this paper, we intend to provide the appropriate light distribution characteristics required in a seaport through optimal lens design, and to solve the heat dissipation problem caused by the use of a high-power light source through heat sink optimization. This paper is organized as follows. In Section 2, theoretical analysis and fabrication of optimized optical lens and heatsink for a high-power LED light source will be shown. Then, the fabrication of a seaport luminaire using an optimized lens and heatsink will be followed. In Section 3, theoretical analysis of prototype LED and conventional HID luminaires in seaport application will be described. Actual measurement results of an LED and conventional HID seaport luminaires in seaport installation will be analyzed. Then, discussion on the results of comparing an LED with HID seaport luminaires will be followed in Section 4. Finally, the conclusion of this paper will be presented in Section 5.