Present Great Developments and Expections for FTTH

FTTH, Fiber to the home, you know. It provides the final customer access technology. There is a situation that fiber optic cables are extended to the ONU (Optical Network Unit) based on the customer’s premises, it also supply the customer virtually unlimited bandwidth for all the applications such as video, voice and high speed data and the speed can reach up to 1G per customer. Related passive optical product: PLC splitter . And the FTTH is future proof, it becomes the only one technology that can meet the requirements for such high bandwidth, the FTTH architecture is shown at the Figure.


We know ONU is required for each client rather than for a group of up to several hundred customers. FTTH is not cost effective at this time, and is dependent upon advances in technology to provide a more cost effective bandwidth on fiber optic cables and effective ONU technology.

Well, FTTH will be many people’s preference. We can know after comprehensive knowledge that the easiest way to provide FTTH is to use passive 1:N optical splitter to divide the optical bandwidth roughly equally between the N customers. Alternatively, a single fiber can also apply for both directions od transmission using wavelength division multiplexing (WDM). The splitting of the optical power among many consumers in a PON (Passive Optical Network) has significant optical power budget.

Recent years FTTH has some developments, such as a proposal for the creation of a GNDG (gigabit national data grid), it can overcome the bandwidth communications requirements for the future and the proposal also allows the use of the alternative access technologies, already discussed, such as XDSL, coax or wireless to provide service at lower data rates. However, interfacing to such solutions may well cost nearly as much as the final FTTH infrastructure. In fact, WDM with optical splitters or optical amplifiers are the main technologies required to implement such a FTTH network. Now WDM systems can provide bandwidths of 40G per fiber, use 16 wavelengths at 2.5 G each, and hope it can reach 100 rerabits in the next 5 years.

Have a Special Look at Fiber Optic Amplifier

Wiki of Fiber Optic Amplifier

An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Optical amplifiers are important in optical communication and laser physics.

Standard of Fiber Optic Amplifier

We know Fiber Optical Amplifiers that design from simple single stage to more complex multistage amplifiers with variable gain evolved as a different viator for system performance by equipment manufacturers and were initially made in house. More recently, the equipment vendors outsourced the design and manufacturing of amplifiers to the component vendors while requiring more than one source in order to control cost and delivery risk. This led to a pseudo-standardization of optical amplifiers with three or four vendors making amplifiers with compatible optical, mechanical,electrical hardware, and software specification.

Optical amplifier is dominated by erbium-doped fiber amplifiers and the leading suppliers have been shipping amplifiers for 10 years or longer. These companies include Oclaro, JDS Uniphase, and Furukawa. Ovum estimates these companies enjoy more than 60% market share of the nearly 200 dollars merchant erbium-doped fiber amplifier market in 2008. Well Fiberstore’s In-line Amplifier is on hot sale.

There are another 25 companies fighting for the remaining revenues. Twenty-one of the remaining optical amplifier companies that still exist today started between 1997 and 2003. All the amplifier suppliers in low cost regions started between 1998 and 2003. And only two new amplifier suppliers have entered the market since 2003, Manlight and Titan Photonics. The Figure showed the optical amplifier for next WDM networks

optical amplifier

Optical Amplifier: Present Status

After nearly five years of focus on cost reduction and reduces progress in innovation. New direction in optical amplifier technology are becoming visible. These are in response to the major trends for the amplified optical networks of higher degree of connectivity and introduction of channels at higher data rates. Agility in amplifiers will be key to the successful deployment of ROADM networks requiring seamless provisioning and recovery in the event of failures. Features such as fast gain control at sub millisecond timescale and rapid spectral adjustments to counter the impairments due to higher order effects (spectral hole during[SHB], Raman spectral tilt in fiber, and polarization dependent loss [PDL]) of components) will be needed on an integrated basis across the whole system. Likewise, continuous demand to increase the OSNR of the signals to support ever increasing channel rates to 100 Gb/s and beyond over ultra-long-haul distances will require every dB to be made available, for example by deployment of hybrid Raman/EDFAs at every repeater site in the network. Another trend is the deployment of high-power cladding pumped amplifiers with watts of output power in the access network for distribution of video and other content. From the commercial standpoint, however, since the industry has become addicted to 15% to 20% price reduction year to year, these new features will have to be delivered at negligible incremental cost.

Warm tips: Fiberstore is a professional fiber optics products supplier, includes different fiber optical amplifier, such as Booster Amplifier, CATV fiber amplifier, DWDM amplifier and EDFA amplifier, even Fibre Splitter, if there you need, welcome to visit our main website:

The value-added function of the modulator based on indium phosphide equipment

Indium phosphide (InP) is a binary semiconductor composed of indium and phosphorus. InP is used in high-power and high-frequency electronics because of its superior electron velocity with respect to the more common semiconductors silicon and gallium arsenide. It also has a direct bandgap, making it useful for optoelectronics devices like laser diodes. InP is also used as a substrate for epitaxial indium gallium arsenide based opto-electronic devices.

The Inp material system has a rich history as an integration platform. The complementary functions or features discussed here have been demonstrated either integrated with Inp-based MZMs, or in epitaxial growth structures compatible with Inp-based MZMs.

The main works of the Inp material system is deep helium implantation has been used to creat point defects in zinc doped InP layers to remove carriers from participating in conduction, with minimal impact to the optical waveguide properties. This helium implant process can be used to isolate electrodes and has been shown to remain stable under extensive thermal, electrical, and optical stress conditions.

Evanescently coupled waveguide InGaAs power detectors insensitive to the optical signal wavelength and input power have been monolithically integrated with the Inp-based MZM, as a simple extension of the spot-size converter fabrication process. These detectors are placed on the complementary and/or in-line out put waveguides to provide feedback for transmitter control.

Leuthold and Joyner have proposed a method to actively tune the power splitting ratio in a 2 x 2 MM and the active tuning of the cross/bar MM1 power splitting ratio betwwen 1 and > 1.7 is demonstrated. The tuning is achieved for < 3 mA of applied current to helium implant isolated edge electrodes on a 10.3 micron 2 x 2 MMI and it produces < 0.15 dB optical loss. This split ratio dynamic range, if applied to the 2 x 2 MMI combiner in the zero chirp modulator design presented, produces sufficient optical power imbalance to move between zero chirp and he optimal negative chirp for maxium dispersion limited reach. A current tunable MMI has also been demonstrated using selective zinc diffusion.

An output power variable fiber optic attenuator is a commonly required function in transmitters for pratical optical communication systems. Early fixed wavelength MZM transmitters used integrated electroabsorption pads on the input of the InP-based MZM to provide this variable optical attenuator function. The same processes used to implement the MMI tunable power optical splitter could be used to implementa wavelength independent variable optical attenuator is simple. The 1 x 1 MMI is a rest ricted symmetric interference device in which only even modes are excited. Therefore, by asymmetrically modifying the refractive index along a selected cross section within the MMI waveguide, such that a phase change of π is induced, mode conversion of the even modes into odd modes is realized. The odd modes are rejected at the MMI output waveguide.

FC Type Variable Fiber Optic Attenuator 1 to 30dB Range

Semiconductor optical amplifiers have been integrated prior to MZMs that use InGaAsP/InP MQW cores, and lossless operation has been demonstrated in 10 Gb/s 1MDD and 40 Gbit/s DPSK applications.

Future applications will benefit from exploration of a single Inp chip for dual polarization Cartesian MZMs, through the monolithic intergration of a TE to TM polarization converter and a polarization combining waveguide element. The demonstrated polarization manipulation functions in InP materials have not used waveguide structures compatible with an MZM. THis commercial application will hopefully spur further reasearch in this area.

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