Posted by: Dale Wright on April 6, 2007 at 8:12 am - Trackback URL

Tags: , ,

At the Optical Fiber Communications Conference last week in Anaheim, CA, NTT Photonics Laboratories unveiled a new optical fiber that functions as both multimode and singlemode fiber, thereby eliminating the need for expensive upgrades and reducing fiber management and ownership costs.

Until now, businesses have had to choose between singlemode or multimode optical fiber for their data transmission and data center needs. However, the dramatic growth in higher-bandwidth connections and transmissions for voice, data, and video from both business and consumers has caused many cable providers, carriers, and data centers to exceed the capacity of their multimode optical fiber. As a result, many have had to invest in major system upgrades to the faster, more expensive singlemode optical fiber system in order to support escalating demands.

NTT says its Dual-Mode Fiber eliminates the need for expensive system upgrades by functioning as both multimode fiber and singlemode fiber. At the outset, when businesses transmission demands are low, Dual-Mode Fiber can be installed and used as multimode fiber at a lower cost than a singlemode fiber system. When demand increases, Dual-Mode Fiber seamlessly transitions to functioning as singlemode fiber, without a complicated and time-consuming fiber-reinstallation upgrade, says the company.

The Dual-Mode fiber also can be used where multimode fiber has already been installed. The coexistence of both multimode and singlemode optical fiber leads to increasing fiber management and ownership costs as the system grows. Each fiber must be utilized for specific functions, and as the system grows and becomes more complicated, additional resources are required to manage the connections properly and avoid misuse. Dual-Mode Fiber is compatible with and easily interconnected with both multimode and singlemode fiber with low optical connection loss to either type, reducing management and ownership costs and eliminating misuse, claim company representatives.

“Dual-Mode Fiber is a unique solution within the marketplace,” contends Dr. Hiromasa Tanobe, senior research engineer at NTT Photonics Labs. “It provides a highly adaptable, lower cost optical fiber solution for emerging companies who anticipate rapid growth of their data transmission needs. The solution also allows existing companies to simplify their fiber management process as they grow, significantly lowering cost of ownership,” he says.

NTT says its Dual-Mode Fiber features a low splicing and return loss connection with conventional singlemode fiber (Typical connection loss: 0.01 dB @ 1.31 micrometer and 0.05 dB @ 1.55 micrometer, return loss: >50 dB) and multimode fiber (Typical connection loss: 0.02 dB @ 850 nm, return loss: >28 dB). The product also features a low bending loss of 5-mm radium (one turn) for singlemode and multimode transmission simultaneously. Dual-Mode Fiber has a cylindrically symmetric structure, which provides relatively flat transparent characteristics for the wavelength region between 1250 nm and 1650 nm (10 turns of 10-mm radium).

Both tough and flexible, Dual-Mode optical fiber is easy to work with and comes in a unique, easy to carry compact optical fiber reel, says the company.

Posted by: Dale Wright on April 5, 2007 at 4:02 pm - Trackback URL

Tags: , , , ,

Molex recently introduced the LC2 metallic optical connectors to provide a ruggedized, all-metal housing version of its LC small form factor (SFF) family. Designed specifically to withstand harsh environments, the new connectors feature the ceramic ferrule-based LumaCore optical termini to resist breakage and achieve superior optical performance, says the company.

With a 1.25-mm LumaCore terminus, the LC2 connectors feature high-performance ceramic ferrules available for singlemode, multimode, and angle-polish applications. They also offer hex register alignment to enable tuning of individual fiber connections. Available in multiple boot styles, including straight, 45 ° , and 90 ° , the LC2 connectors support many cable sizes and applications, including 900-microns and 1.20-, 1.60-, 1.80-, and 2.00-mm.

The LC2 connectors are capable of continuous operating temperatures up to 135 ° C, with short term temperatures of up to 150 ° C when used with high temperature optical fibers. Additionally, with no plastic components, there is little or no out-gassing, allowing these connectors to accommodate space and high-vacuum environments, say Molex representatives.

The LumaCore terminus utilized in the LC2 is also interchangeable with the Molex MXL-38999 circular connector for ease of polishing, testing, inspecting, and troubleshooting across the two connector styles. The removable color coded anodized-aluminum connector housing with a stainless steel latch enables customers to directly inspect fiber bonding areas and replace connector body components without fiber re-termination.

When terminated, the LC2 connectors meet a minimum of all the dimensional and performance requirements of Telecordia GR-326-CORE and TIA/EIA-604-10a (FOCIS-10).

Posted by: Dale Wright on April 5, 2007 at 4:00 pm - Trackback URL

Tags: , , , , , , , , ,

Yokogawa Electric Corp. and Fujitsu Ltd today announced the joint development of what they claim are the world’s first practical 40Gbps optical transmission technologies using differential quadrature phase shift keying (DQPSK). The two companies say they are planning to incorporate the technologies in various new products for 40Gbps ultra high-speed optical transmission networks.

The proliferation of optical access networks that directly connect households via optical fibers and the construction of next-generation networks have led to a increasing demand for greater capacity in inter-city optical transmission networks. In order to meet this demand, carriers are considering an increase in maximum transmission speed from the 10Gbps of today’s optical transmission networks to 40Gbps.

Typically, when transmission speed is increased, distortion caused by polarization mode dispersion (PMD) becomes pronounced, limiting transmission reach. For example, transmission reach is limited to a maximum of 100 km when transmitting a 40Gbps signal using a standard binary modulation in an optical fiber that meets the PMD specification (0.2 psec per square-root-kilometer) recommended by the ITU-T. Thus, inter-city transmission, which requires long-distance transmission of more than several hundred kilometers, has not been possible.

Seeking to overcome this obstacle, advances are being made in investigating DQPSK-type transmission, which is tolerant to waveform distortion due to PMD, and its high performance has been confirmed in the laboratory experiments. However, the configuration of a DQPSK format is complex, and thus large size and high power consumption of the optical transceivers have proved to be challenges.

Yokogawa Electric and Fujitsu Limited, in cooperation with Fujitsu Laboratories Ltd, have successfully developed what they claim are the world’s first practical 40Gbps DQPSK optical transmission technologies, including:

DQPSK LN optical modulator
The LN optical modulator for DQPSK modulation, which was developed by Fujitsu and operates with the world’s lowest drive voltage, enables a compact optical transmission component design and lower power consumption.

Dedicated ICs and devices that enable DQPSK
Compact, low power consumption, dedicated ICs and other devices that enable DQPSK, including a driver device optimized for the DQPSK LN optical modulator; optical/electrical conversion devices that operate stably despite PMD waveform distortion; and clock and data recovery devices were developed with Yokogawa Electric’s InP Hetero-Junction Bipolar Transistor (InP HBT) technology.

Compact optical transmission module
Control technology was developed that allows the newly developed key devices to operate in a stable manner. The companies also developed a mounting technology that enables a compact size, making possible a compact 110- x 320- x 40-mm package equipped with all functions necessary for 40-Gbit/sec DQPSK in the transmission equipment and a low-power consumption of 35 W (with case temperature of 72 ° Celsius).

According to the companies, 100 units of 40Gbps DQPSK optical transceivers were manufactured, and transmission performance and stable operation–despite environmental changes such as temperature fluctuations and variations in supply voltages–were confirmed. Furthermore, the transmission reach as limited by PMD was found to be approximately eight times better than that of standard binary modulation, say the companies.

The resulting technology is expected to significantly reduce the time it will take to implement major inter-city high-capacity optical networks.

The new technologies were developed under a strategic partnership, established between Yokogawa and Fujitsu in March of 2006, to jointly develop core system technologies and key components for ultra high-speed optical transmission systems with the cooperation of Fujitsu Laboratories Ltd. Sample products were on display at last week’s OFC/NFOEC Conference in Anaheim, CA.

Posted by: Dale Wright on April 4, 2007 at 8:34 pm - Trackback URL

Tags:

Here are all the interesting links I found the last few days:

Posted by: Dale Wright on April 4, 2007 at 9:17 am - Trackback URL

Tags: ,

If you are like me, converting numbers into dB values has not come easy. Well, I recently attended a training class offered by my employer that, as part of the up front refresher material, provided the best method I have ever seen for quickly calculating the correct answer (next to using a calculator of course).

Step 1:

The first step requires a little memorization. You will need to memorize all the dB values for the numbers 1 through 10. Here is a good estimation for each value:

1 = 0 dB
2 = 3 dB
3 = 5 dB
4 = 6 dB
5 = 7 dB
6 = 8 dB
7 = 8.5 dB
8 = 9 dB
9 = 9.5 dB
10 = 10 dB

While these aren’t exact numbers, they are close enough for quick, off the cuff, calculations. Also, we are ignoring fractional values because this method is meant for quick estimates, not exact calculations.

Step 2:

The next step is the actual conversion. For a number that is N digits long, the dB value will be 10 x (N-1) plus the dB value of the Nth digit (furthest to the left).

For example, convert 7,6453,785,473 to dB.

This value is 11 digits long, so the estimated dB value is (10 x 10) + 8.5) or 108.5 dB.

Plugging that number into a calculator yields a value of 108.8 dB for an error of 0.3 dB.

It works for any number. Of course, the larger the number, the higher the margin of error will be.

Let’s try it one more time:

Convert 584,369,854,587,523,698,452,566

This value is 24 digits long, so the estimated dB value is (23 x 10) + 7) or 237 dB.
The calculator value is 237.6 dB

Hope this helps.

Previous Page Next Page
Outdoor Shop sex herbal v viagra soft tabs study uk cialis soft tabs body building from sports supplement viagra and pharmacy humor canadian rx cialis discount sales allwam mature big boobs party hardcore mature grany mistress SEX MOM GIRLS mature sex drunk nude party full free sex famous lesbian pornstar sex porno casting buy cialis cheap viagra sale uk viagra without prescription mail order viagra soft tabs cheap drugs best herbal levitra where to buy cialis soft tabs online porn sex mature videos porn blog sex teen porn videos porn