The Upconversion Technology Based On Injection-locked Laser

With the development of the information age，the incressing of the demandwhich people need more bandwidth of the wireless communication, makes thecommunication based on Radio over fiber which combines the advantages of fiberoptic and wireless transmission becoming a research hotspot.The RoF technology isconsidered to be the key technology for the design of the new generationalbroadband mobile communication.This article focuses on the generation of thehigh-frequency optical wireless communication load carrier signal (microwave/millimeter wave).A new upconversion scheme based on laser injection isproposed.This paper mainly includes the following aspects:In this paper the upconversion theory based on the laser injection locking isanalysised,modeled and simulated.The four-wave mixing and self-phase modulationtheory are analyzed.And the laser rate equations are for the modeling andsimulation.The theory is tested in the experimental system,then the experimentalscheme is proposed.In this paper a microwave photon upconversion scheme based on a verticalcavity surface emitting laser without local oscillator is proposed.The program is thatinjecting the relatively low pseudo-random bseband signal into the VCSEL.Use thehigher harmonics injected signal to inject-lock the VCSEL. The inject-locked laserwavelength beat coherently with the original optical signal in the cavity whichgenerates the amplitude modulated microwave signal.In the experiment use2.5Gb/sNRZ intensity modulated signal to inject-lock the VCSEL,that achieve a carrierfrequency of14.3GHz microwave photon upconversion, and the carrier phase noise is-81dBc/Hz@10KHz.Adjust the wavelength and power to achieve further7.5GHz~23GHz frequency carrier then the feasibility of the structure is verified.And do theBER performance and system analysis, system consideration1dBm Only using theinexpensive VCSEL to achieve the upconversion signal to provides a low costsolution ideas for the wireless-Access Network photon optical mixing the microwavesignal generation technique.In this paper, the scheme is improved besed on the experimental system whichconsises of VCSEL and external modulator. A improved upconversion schemebased on directly modulated DFB laser injecting FP laser is proposed.Use2.5Gbps baseband signal directly modulated the DFB laser,then the direct spectral isbroaded,which generated high side band.The high side band is locked andamplificated by the FP laser,which beats with the original wavelength to generat the20GHz,30GHz,40GHz microwave millimeter-wave signals. Since broadening thespectrum directly modulated lasers more visible the higher frequency upconvertedsignal can be generated.At the same time phase noise is tested:-78dBc/Hz@10KHzwhile the signal is30GHz.The high quality microwave signals are generated whichproposes a new scheme for the higher upconversion RoF technology.