Fiber Optic Tutorials

This is a continuation from the previous tutorial - Multimode, large-core, and plastic clad fibers     1. INTRODUCTION In applications that utilize specialty optical fibers, very often there are requirements placed on the optical fiber design that are not conducive to the launch or delivery requirements placed on the proximal and distal ends of the fiber. For example, in high-power medical applications, such as laser angioplasty or laser lithotripsy, a small-fiber diameter may be required so the fiber probe assembly will be able to bend easily inside the small blood vessels of the body. However, this may cause difficulty on...

This is a continuation from the previous tutorial - Real-time implementation of high-speed digital coherent transceivers     1.  INTRODUCTION Advanced modulation formats, together with wavelength-division multiplexing \(\text{(WDM)}\) and polarization-division multiplexing \(\text{(PDM)}\), have become key enablers to increase the spectral efficiency and the overall capacity per fiber. Coherent optical transmission has been employed in long-haul communications with channel data rates at \(\text{100G}\) and beyond and with transmission distance typically beyond \(\text{2000km}\). PDM quadrature phase-shift keying \(\text{(QPSK)}\) is the format of choice in the current deployed \(\text{100G}\) networks. Next-generation \(\text{400G}\) networks may utilize \(\text{PDM}\) 16-ary quadrature-amplitude modulation \(\text{(16QAM)}\). Coherent transmission technology...

This is continuation from the previous tutorial - Reflective and catadioptric objectives     1. INTRODUCTION This chapter provides an overview of optical scanning techniques in context with their operational requirements. System objectives determine the characteristics of the scanner which, in turn, influence adjacent system elements. For example, the desired resolution, format, and data rate determine the scanner aperture size, scan angle, and speed, which then influence the associated optics. The purpose of this chapter is to review the diverse options for optical scanning and to provide insight to associated topics , such as scanned resolution and the reduction of spatial errors....

This is a continuation from the previous tutorial - Elliptical core and D-shape Fibers     1. INTRODUCTION After years of playing ensemble roles, large-core multimode fiber has stepped into the spotlight of fiber optic technology and innovation. From the smallest of veins in the human body, to the vastness of the universe, when the need for every photon matters, the advantages of large-core \((>200\) \(\text{micron})\) multimode specialty fibers are taking the lead. As the name implies, multimode fibers are those types of fibers designed to carry multiple rays of light or modes. There are two types of multimode fibers:...

This is a continuation from the previous tutorial - Carrier recovery in coherent optical communication systems     1.  ALGORITHM CONSTRAINTS Coherent optical transmission systems at 100 Gb/s use baud rates of 28 Gbaud or beyond, with the receiver \(\text{ADCs}\) usually using two times oversampling, that is 56 Gs/s and beyond, to convert the received signals from the analog to the digital domain. Standard cell logic in modern complementary metal–oxide–semiconductor \(\text{(CMOS)}\) technology cannot operate at this high sampling rate of the \(\text{ADCs}\). The preferred clock speed for standard logic is usually in the range of a few hundred megahertz, which means...