Routing power: a metric for reconfigurable wavelength add/drops

Abstract

/ OFC 2002 / TUESDAY AFTERNOONwavelengths between 1550 and 1620 nm, corresponding to a tuning range of 70 nm.The full width at half maximum (FWHM) of the devices was around 35 nm. The quantum efficiency measurements were done at 5 V reverse bias under 0.5 mW optical input power. When we increased the reverse bias beyond 3 V the active layer was fully depleted, and the quantum efficiency increased 6% with respect to zero bias. The responsivity of the PDs were also measured under various re~erse biases up to 6 mW optical power, which was the maximum power that could be abtained from the laser. Fig. l(b) shows the photocurrent versus input optical power at the resonance wavelength of 1572 nm. Under 3 V and higher re~erse biases, the PDs had a linear photoresponse up to 6 mW optical power. At 6 mW optical power, the device exhibited a 5 mA photocurrent. The saturation was mainly due to the electric field screening caused by photo-generated carriers?High-speed measurements were made with a picosecond fiber laser operating at 1550 nm. The 1 ps FWHM optical pulses from the laser were coupled to the active area of the p-i-n photadiodes by meam of a fiber probe. At zero bias, the responseofthephotadetectorshadalongtaildue to the diffusion of the carriers in the active layers. Measurements were done under bias to deplete the active layer completely and to get rid of the diffusion tail. Above 3 V reverse bias, we got a Gaussian response with a short tail. Fig. 2 shows the temporal response o f a Small area (5 x 5 hm') photodetector measured at 7 V bias by a 50 GHz sampling scope. The photodiode output had a 16 ps FWHM. The measured data was corrected by deconvolving the effect of the 40 GHr bias-tee. After the deconvolution, the device had a 3-dB bandwidth of 31 GHz. Larger area devices (80 pm2) also showed similar responses, which showed that the temporal responsewas limited by the transport of the photogenerated carriers.In conclusion, we have demonstrated highspeed, and high-efficiency resonant cavity enhanced (RCE) InGaAs based p-i-n photodetec~ tors. A peak quantum efficiency of 66% was measured along with 31 CHz bandwidth, which corresponds to 20 GHz bandwidth-efficiency product. The photoresponse was linear up to 6 mW optical power, where the devices exhibited 5 mA photocurrent. Time (psec)TuW6 Fig. 2. Temporal response of the photodetector with a 16 psec full width at half maximum. The inset shows the deconvolved frequency response obtained from the fast Fourier transform of the temporal dedetector response. No. INT-9906220, Turkish Department of Defense Grant No. KOBRA-001 and Thaler IP8.04 1. M.S. Unlu and S. Strite, "Resonant cavity enhanced (RCE) photonic devices:' 1. ,-Highspeed >90% quantum efficiency p-i-n photodiodes with a resonance wavelength adjustable in the 795-835 nm range:' Appl. power high-speed photodetectorbDesign, analysis, and experimental demonstration': IEEE Trans. Mimownve lkeory Tech., vol. 45, "0.8, l32&l33l,(1997). TUX 430 p m 4 0 0 pm 304 A-D Network Design 2 lane M. S h " n s , Corvir Cor...

Optical network scaling: roles of spectral and spatial aggregation

“…All spectral and spatial aggregation techniques increase switching granularity from the level of constituent channels to that of superchannels, decreasing optical switching hardware complexity, but potentially sacrificing routing flexibility, which is commonly quantified in terms of routing power [57,58].…”

“…A drawback of decreasing the number of ports is a reduction in the number of routable input and output port combinations. Following [57,58,60], we define the routing power as log( ) log( )…”

A Scalable Model for the Performance Evaluation of ROADMs with Generic Switching Capabilities

“…In [17] and [18] blocking in ROADM optical networks is investigated and both papers consider cases of different multi hop ROADM networks. Also [19], [20], [21], [22] investigate the performance of ROADMs using a theoretical model called the "routing power" model. The minimum number of ROADMs required for accommodating a given traffic load for a specific ROADM architecture in ring optical networks and an acceptable wavelength blocking probability has also been carried out [23].…”

Evaluating Wavelength Routing Power of Dynamic ROADM Networks(cat-I) for Various Traffic Types

“…Each of those connection states can be represented by a connection vector with elements equal to one or zero, depending on whether the corresponding wavelength is dropped or expressed [13]. An expressed wavelength is the wavelength that just passes through the ROADMS without being added/dropped.…”

“…An expressed wavelength is the wavelength that just passes through the ROADMS without being added/dropped. For unidirectional ROADMS that do not have wavelength conversion functionality, routing power is defined as [13] …”