多项选择题

Click the Exhibit button. When designing a DWDM system with multiple amplified spans, a pre-amp is needed at Site B to (). (Choose three.)

A. offset the OADM loss at site b 
B. overcome the high multiplexer loss at site a 
C. amplify signal levels after the high loss through Fiber Span 1
D. adjust add channels at site B to be at the same level as the passthrough channels
E. ensure that the per channel power is higher than the minimum needed for the post-amp at Site b


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1.单项选择题How is a Thin Film filter fabricated?()

A. The glass core is doped with an Erbium in periodic segments of the fiber.
B. Layers of high index ?and low index ?material are deposited on a glass substrate.
C. Thin layers of silica glass are placed onto wafers to produce a prism-like effect.
D. Fiber is etched with an ultraviolet laser that is precisely spaced for specific wavelength filtering.

3.单项选择题If the power is 0 dBm, what is the power in mW?()

A.0mW
B.1mW
C.10mW
D.1.5mW

4.单项选择题Which device creates an OEO conversion?()

A. amplifier
B. attenuator
C. regenerator
D. light emitter
E. optical switch
F. optical receiver
G. fiber-optic cable

6.多项选择题What three in combination are factors that can cause four-wave mixing in fiber-optic cables? ()(Choose three.)

A. low optical power
B. high optical power
C. few optical channels
D. many optical channels
E. low chromatic dispersion
F. high chromatic dispersion
G. too much power differential in the optical channels

7.单项选择题Why are the 1300 nm and 1550 nm regions of the fiber spectrum primarily used for optical communications?()

A. They are both regions of lowest loss.
B. They are both regions of low reflections.
C. They are both regions of low index of refraction.
D. They are both regions of low chromatic dispersion.
E. They are both regions of low Polarization Mode Dispersion (PMD).

8.单项选择题What is an advantage of an externally modulated laser over a directly modulated laser?()

A. lower cost
B. higher chirp
C. easier to manufacture
D. higher dispersion tolerance
E. higher optical signal-to-noise ratio

9.单项选择题What is the difference between the transmitted power and the sensitivity of the receiver?()

A. OSNR
B. dispersion
C. attenuation
D. power budget
E. amplifier spacing
F. four wave mixing

10.多项选择题Which three technologies are used to reduce chromatic dispersion accumulation in fiber-optic transmission systems? ()(Choose three.)

A. PIN photodiodes
B. zero-chirped lasers
C. Erbium-doped fiber amplifiers
D. dispersion compensating fiber
E. dispersion compensating Bragg grating

最新试题

Which timing mode is appropriate for a SONET NE that is adjacent to a SONET NE using BITS-1 timing source?()

题型:单项选择题

In the OSNR model for EDFA amplifiers, SNR OUT = 1/(1/SNR IN + FhvB/P IN ), what does SNR IN represent?()

题型:单项选择题

Click the Exhibit button. What is the maximum allowable loss budget between the ONS 15216 Mux (left side) composite output and the ONS 15216 Demux (right side) composite input, with the optical values given in the exhibit? ()(Assume the worst case loss of 4.5 dB for 15216 200 GHz Mux/Demux and ignore power penalties or extra margin.)

题型:单项选择题

SONET Code Violations (CVs) totals in the PM tables are actually an accumulation of the number of ().

题型:单项选择题

Which device creates an OEO conversion?()

题型:单项选择题

UPSR protection switching is initiated by (), while BLSR is initiated by ().

题型:单项选择题

What are three factors that limit the maximum distance of an amplified optical signal without regeneration? ()(Choose three.)

题型:多项选择题

If the dispersion of a given fiber is 17ps/nm*km at 1550 nm and zero at 1310 nm, then what is the accumulated dispersion of an ITU wavelength after it travels 200 km?()

题型:单项选择题

Given the formula: (Fiber Attenuation * Km) + (Splice Attenuation * # of Splices) + (Connector Attenuation * # of Connectors) + (Optical Fiber or OADM) + Buffer(Fiber aging)) With regard to SONET/SDH optical calculations, what will the given formula provide?()

题型:单项选择题

SONET Path Terminating Equipment (PTE) requires which three line codes to be supported for DS1 and DS3 circuits?() (Choose three.)

题型:多项选择题