Study On Novel Tunable Distributed Feedback Semiconductor Laser And Laser Array Based On Reconstruction Equivalent Chirp Technique

The low-cost tunable distributed feedback(DFB)semiconductor laser and laser array are investigated in this thesis.Firstly,the application,research significance and status both at home and abroad of the tunable semiconductor laser are introduced.Then the reconstruction equivalent chirp technique is described,as well as the fabrication method of sampled grating.With the help of the transfer matrix method algorithm,the assisted phase shift corrugation pitch modulation(APS-CPM)DFB semiconductor laser and laser array with suppression hole burning effect are investigated.The photon distribution and spectra are simulated.The photon density distribution in APS-CPM semiconductor laser is much flatter than that of ?/4 phase shifted semiconductor laser.The experimental results show that the spatial hole burning effect was suppressed in this structure as theoretically predicted.The 32 channels with 100 GHz spacing are got with the APS-CPM semiconductor laser array.The tuning wavelength range is 1546.12 nm to 1570.83 nm.The tunable DFB semiconductor laser and laser array with phase shift introduced by injection current are studied.Firstly,the transmission spectra,photon distribution are simulated.The phase shift can be changed if we adjust the injection current of the electrodes in the experiment.Laser array with 63 channels and 50 GHz spacing are experimentally obtained.The tuning wavelength range is 1542.54 nm to 1567.54 nm.The ?/4 phase shifted DFB laser and laser array are investigated.The good single longitudinal mode is achieved in the experiment.The tuning wavelength range of single laser is 1.34 nm when the injection current is from 20 mA to 110 mA.The laser array is also fabricated with 40 channels and 50 GHz spacing.The tuning wavelength range is 1551.32 nm to 1567.54 nm.Multisection DFB tunable laser tuning by injection current are investigated.Firstly,the transmission spectra are simulated.The Bragg wavelength is designed to aviode the overlap between the neighboring lasers' stop-bands.So the interference between the neighboring lasers may be eliminated.At the temperature of 20?,the wavelength tuning range of each laser is about 3.4 nm to 3.6 nm when the injection current is from 30 mA to 170 mA.And the side mode suppressing ratios(SMSRs)are all over 35 dB.The tuning speed is about 10 ms to 30 ms.By tuning the injection currents,the 23 channels with 50 GHz spacing are acheived.The tuning wavelength range is 1554.14 nm to 1563.05 nm.These results investigated in this thesis may help to realize low-cost tunable DFB semiconductor laser and laser array in the future.