Studies On Optical Wavelength Conversion Driven By RF Signals

The development of modern optical communications, especially the developmentof ne w WDM t echnology, has p roposed n ew ch allenges t o t he p resent opticalwavelength conversion technology. In this paper, we investigate one novel opticalwavelength c onversion t echnology using th e I/Q modulator theoretically andexperimentally, analyze t he i mpact f actors o f t he co nversion and ach ieve theconversion of optical multi-wavelength sources. Besides, the generation of stable andhigh-quality multi-carrier optical source and the detection of FBG are demonstratedby using the I/Q modulator-based recirculating frequency shifter (RFS). This paperfocus on the followings:(I). Theoretical research of wavelength conversion using the I/Q modulator1. The theory and impact factors for single wavelength conversion using the I/Qmodulator is investigated. The possible generation of noise during the wavelengthconversion process is also analyzed.2. The measurement principle of line width for single longitudinal mode laser isanalyzed.3. T he generation principle o f m ulti-wavelength l ight s ource (△λ=0.8nm，△γ=100GHz) using current-driven SOA and high-birefringence fiber loop mirror isanalyzed.4. The theory of the generation of multi-wavelength light source (△λ=0.08nm，△γ=10GHz) by using the I/Q modulator-based recirculating frequency shifter (RFS)is investigated.(II). Experimental research of wavelength conversion using the I/Q modulator1. The single wavelength conversion using the I/Q modulator is achieved. Theinfluences of different factors originated from two radio frequency (RF) bias voltage,phase modulator voltage and RF are all investigated.2. The line width of DFB laser and the corresponding wavelength convertedoptical signal are both measured, showing that the line width of converted opticalsignal is not broadened significantly.3. The w avelength c onversion for multi-wavelength optical si gnals using I/Qmodulator is achieved and different frequency conversion intervals (8GHz,10GHz,12GHz) are demonstrated. The influences of different factors originated from tworadio f requency (RF) b ias v oltage, phase m odulator vol tage a nd RF are a ll investigated. The stability o f m ulti-wavelength s ignals during t he wavelengthconversion process is also analyzed.4. Stable and high-quality multi-wavelength optical signals (10GHz frequencyinterval, up to25channels within3dB power difference) are achieved by using theI/Q modulator-based recirculating frequency shifter (RFS).5. One nov el detection a nd de modulation system (by mapping w avelengthmeasurement t o t ime m easurement) ba sed on R FS i s pr oposed, us ing RFS forfrequency conversion and FBG for filter. The feasibility study is conducted by usingthis system for temperature sensing detection.