Fiber Optic Tutorials

This is a continuation from the previous tutorial - optical fiber lasers.   Semiconductors are important materials. Because of their unique electronic properties. they are the materials of choice for modern electronic devices. Silicon, in particular, has become the most important material for the electronics industry. Besides their unique properties for electronics applications, semiconductors also have many other important properties that are very useful for photonic device applications. In earlier tutorials, we have already seen that III-V semiconductors are useful materials for optical waveguides and electro-optic devices. Many semiconductors are also used for acousto-optic devices and nonlinear optical devices. In...

This is a continuation from the previous tutorial - pulsed lasers.   A fiber laser can be constructed by simply creating some form of optical feedback to a fiber amplifier. Nevertheless, while most interest in fiber amplifiers has concentrated on the 1.3- and 1.5-μm spectral regions for optical communication systems, the development of fiber lasers has covered a broad spectral range, from a holmium-doped fiber laser at 550 nm and a praseodymium-doped fiber laser at 610 nm in the visible spectral region to an erbium-doped fiber laser at 2.7 μm and a holmium-doped fiber laser at 2.9 μm in the infrared...

This is a continuation from the previous tutorial - laser power. In the CW (continuous wave) operation of a laser, the laser is pumped continuously at a constant pumping level, and the loss of the laser cavity is also kept constant so that the laser has a constant output power when it reaches steady state. A laser can also be pulsed to deliver short optical pulses at its output. In pulsed operation, the net gain seen by the laser field is not kept constant but is temporally varied by pulse pumping the gain medium and/or by modulating the cavity loss....

This is a continuation from the previous tutorial - laser oscillation. In this tutorial, we consider the output power of a laser. Because the situation of a multimode laser can be quite complicated due to mode competition, we consider for simplicity only a homogeneously broadened, CW laser oscillating in a single longitudinal and transverse mode. Therefore, the parameters mentioned in this tutorial are not labeled with mode indices because all of these parameters are clearly associated with the only oscillating mode being considered. The simple Fabry-Perot cavity that contains an isotropic gain medium with a filling factor \(\Gamma\) as shown...

This is a continuation from the precious tutorial - resonant optical cavities.   In the previous tutorial - resonant optical cavities, it is mentioned that a practical laser device can be constructed by placing an optical gain medium inside an optical resonator. The gain medium provides amplification to the intracavity optical field while the resonator provides optical feedback. A laser is basically a coherent optical oscillator, and the basic function of an oscillator is to generate a coherent signal through resonant oscillation without an input signal. Therefore, no external optical field is injected into the optical cavity for laser oscillation....