## Expression for Multiplication

An avalanche photodiode composed of a p+-i-n+ multiplication region extending from x 0 to x Lm and a depletion region extending to x wj is considered and modeled as shown in Fig. 9.4. The stack of multiple layers with p+-i-n+-n -n+ (substrate) impurity doping profile is shown in Fig. 9.4(a) and (b). The electric field distribution when a reverse bias is applied to the device is drawn in Fig. 9.4(c). Figure 9.4(d) indicates Fig. 9.4 Simplified model of avalanche photodiode (a) structural concept...

## 08 06 04

Fig. 3.6 Differential quantum efficiency versus cavity length as a parameter of internal loss (1480 nm laser) Differential quantum efficiency decreases with cavity length. Internal quantum efficiency of 84 is assumed. Internal quantum efficiency more than 90 is obtained for a well-designed 980 nm laser. 0 200 400 600 800 1000 1200 Q Cavity Length ( im) Fig. 3.6 Differential quantum efficiency versus cavity length as a parameter of internal loss (1480 nm laser) Differential quantum efficiency...

## 953 Thin Multiplication Region Apds

It has been observed that the excess noise from Mclntyre's theory does not provide a good fit to the multiplication curves and that it overestimates the multiplication noise and underestimates the gain-bandwidth products for devices with thin multiplication regions 75-77 , After an ionization event a carrier needs to travel a certain distance before it can gain sufficient energy from the electric field to have a certain ionization probability. The distance is referred to as the dead-space or...

## References

Suematsu, and S. Arai, GalnAsP InP integrated laser with butt-jointed built-in distributed-bragg-reflection waveguide, Electron. Lett., 17 (1981) 945-947. 2. T. L. Koch and U. Koren, Semiconductor photonic integrated circuits, IEEE J. Quantum Electron., 27 (1991) 641-653. 3. E. H. Li, Semiconductor Quantum Well Intermixing (Gordon and Breach Science Publishers, Amsterdam, 2000). 4. R. Bhat, Current status of selective area epitaxy by OMCVD, J. Cryst. Growth, 120 (1992)...

## Optical Confinement Factor

Optical confinement factor T is the very important parameter that describes the laser action as given in the content. It is derived from Maxwell's equation for the multi-layer waveguide. The calculation model of the multiplayer waveguide structure is shown in Fig. 3.36. t- and y-axes are perpendicular and parallel to multilayers, respectively. Optical field propagates along the j-axis. In lattice-matched and compressive-strained MQW lasers, lasing mode is fixed to be transverse electric field...

## Hybrid Integrated Module on PLC Platform

It is widely recognized that the bandwidth in customer premises will only be possible if the fiber-based network is extended from metro areas to customer premises. Bringing optics closer to the end-users, especially in fiber-to-the-home (FTTH), can be realized based on the availability of the low-cost, Fig. 13.22 Picture of the 10 G receiver (APD and pre-amplifier) module, Fig. 13.22 Picture of the 10 G receiver (APD and pre-amplifier) module, architecture of such kind complicates the assembly...

## 744 Bit Error Ratio Testing

In the simplest case the fundamental measure for the transmission performance of an electroabsorption modulator is how accurately a receiver can determine the logic state of each transmitted bit. This figure of merit is called the bit error ratio. It is defined as the number of errors in a given time interval t divided by the total number of bits transmitted in that same time interval. The equipment used to measure this is known as a bit error ratio tester or BERT. It consists of three main...

## 722 Quantum Confined Stark Effect

Excitonic effects have a very dramatic influence on the optical properties of semiconductors, particularly near the band edge. Below the band edge there is a strong excitonic resonance in the absorption and emission behavior. This causes a strong enhancement of the absorption process above the bandgap, especially in three-dimensional systems. Confining the exciton in a quantum well greatly increases the binding energy along with the oscillator strength. This increased binding energy allows the...

## 2

Surface-Emitting Laser in Long Wavelength Band 5.4.1. GalnAsP InP VCSEL The first surface-emitting laser device was demonstrated by using GalnAsP InP system in 1978 and published in 1979 3 . The importance of 1300 or 1550 nm devices is currently increasing, because parallel lightwave systems are really needed to meet the rapid increase of information transmission capacity in local area networks (LANs). However, the GalnAsP InP system conventionally used in trunk communication systems with...

## 941 Separated Absorption And Multiplication Structure

Ino.53Gao.47As (Eg 0.75 eV) is the narrowest bandgap mixed alloy material lattice-matched to InP (Eg 1.35 eV). It has a large absorption coefficient for the whole l-(j.m-wavelength range (absorption coefficient both at 1.3-n.m and 1.55-n.m is 1.2 x 104 cm-1 and 8 x 103 cm-1, respectively). The narrow bandgap InGaAs light absorption layer can't layer, and InP layer are prepared by a certain epitaxial growth technique. A p-n junction is formed inside the InP layer. The n-InP, n-InGaAsP, and...

## 441 Using A Vernier Effect Between Two Comb Reflectors

The Vernier caliper, invented by the French scientist Pierre Vernier (15801637), is a well-known tool for high-resolution length measurements. The principle is illustrated in Fig. 4.11. The caliper consists of two graduated scales, a main scale like a ruler and a second scale, the Vernier, which slides parallel to the main scale. The two scales have a small relative pitch difference, e.g. 1 20, such that a shift of the slider by an amount Sx leads to a shift of the point where tick marks on...

## C Disordered MQW

Fig. 10.1 Waveguide joint structures (a) butt-joint structure, (b) evanescent wave-coupled (taper) waveguide, (c) disordered MQW, (d) selectively grown structure. mainly a result of diffusion in metal-organic vapor phase epitaxy (MOVPE, also called MOCVD, OMVPE, and OMCVD). By using this technique, all waveguide layers in monolithically integrated devices such as the active layer, the modulation layer, and the passive waveguide layer can be formed simultaneously. This significantly simplifies...

## Avalanche Multiplication Process

The most important physical process in an avalanche photodiode is the avalanche multiplication process that appears in the functional diagram of Fig. 9.1. In a semiconductor material, carriers traveling through the high electric field region (> 1 x 105 V cm) gain energy from the field and generate additional free electron-hole pairs by impact ionization of valence electrons into the conduction band, leaving free holes in the valence band. The secondary electrons can be accelerated by the...

## 75 Electroabsorption Modulators Integrated with Lasers

One of the biggest advantages of the EA modulator is its potential for integration with other semiconductor-based photonic devices. In fact some of the earliest examples of photonic integrated circuits are electroabsorption modulated lasers or EMLs which combine a conventional distributed feedback (DFB) telecommunication laser with a monolithically integrated electroabsorption modulator 21 . These devices have seen widespread application in a large number of 2.5 and 10 GB s fiber optic...