The Comparative Study of the Temperature Distribution of Fiber Laser with Different Pump Schemes

Mostafa Abouricha, Abdelkader Boulezhar, Nabil Habiballah

Chouaib Doukkali University, Faculty of Science, Laboratory of Condensed Matter of Physics, El Jadida, Morocco.
Hassan II Casablanca University, Faculty of Sciences-Ain Chok, Laboratory of Theoretical and Applied Physics, Casablanca, Morocco.

DOI: 10.4236/ojmetal.2013.34010                

Abstract

Based on the structure of the long fiber laser (YDCFLs) with different pump schemes using high pump power, the nonlinear coupled and heat dissipation equations are solved numerically. Using the finite-difference method, we have determined the temperature distribution along the radial and axial directions of the fiber laser (YDCFLs) for the forward pump schemes of 200 W with reflection Rp2, backward pump schemes of 200 W with reflection Rp1 and for bidirectional pump scheme of 100 W each side. The results are: the temperature distribution for bidirectional pump mode is more even than that for forward pump with reflection Rp2 and than that for backward pump with reflection Rp1. The results show that the maximum temperature difference between different schemes is 57.51°C, and when the air-clad width decreases, the temperature in the core regions also decreases and does not affect to the cladding radius regions. We summarize that the temperature in the core and in cladding radius regions decreases when the outer radius cladding increases.

Keywords

Pump Scheme; High Power Fiber Laser; Temperature Distribution

1. Introduction

The double-clad fiber laser (DCFLs) have several applications in modern telecommunication, medical instruments, military, defense and material surface processing, because of some unique advantages including high conversion efficiency, excellent beam quality, less thermal effect [1-3]. The continuous wave emission up to kWlevel has been reported [4,5]. A new type of photonic crystal fibers (PCFs) has opened numerous axes in research; this is due to its unique properties such as endlessness.

Thermal effect in Single mode guiding in high-power fiber laser has attracted much attention in recent days [6, 7]. Also, the developments of cladding-pumped fiber technology and high brightness semiconductor diode pump lasers enabled have been used to save energy [8]. The evolution of the temperature and the influence of the core, inner-clad, air-clad and outer clad, on the shape of optical fiber have been studied [9].

Numerically, Shang [8] has investigated the output power characteristics of YDCFLS with different pump schemes, finding the bidirectional pump scheme is compatible with the backward with R_p1 = 0 and forward pump scheme with R_p2 = 0. However, the backward pumped YDCFL with R_p1 = 0.98 has the highest conversion efficiency; while the forward pumped YDCFL with R_p2 = 0.98 has maximum output power per meter.

In this paper, we have investigated numerically the theoretical and numerical analysis of 2D Temperature field by solving the transient heat conduction equations comparing in detail the temperature distributions in the backward pump schemes with R_p1, forward pump schemes with R_p2 and bidirectional pump scheme. The results show that the maximum temperature in the two-end pump is 96.89˚C, in the forward pump is 148.4˚C and in the backward pump is 154.4˚C. Thus, the temperature distributions for two-end pump mode is more even than that for forward pump with reflection R_p2 = 0.98 and backward pump with reflection R_p1 = 0.98 mode.

2. Theoretical Analysis

Figure 1 demonstrates the schematic of YDCFL. For the convenience of analysis, the pump light and output laser

Conflicts of Interest

The authors declare no conflicts of interest.

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