The influence of sub-wavelength grating on wavelength tuning range in VCSEL

By comparing the structures of (Inter-cavity sub-wavelength grating) ISWG-VCSEL, (Top DBR inter-cavity sub-wavelength grating) TIWG-VCSEL, and (Surface sub-wavelength grating) SSWG-VCSEL, we find the structure of ISWG-VCSEL wavelength tuning range is the largest, its tuning range can reach 51nm. Then based on ISWG structure, the influence of grating parameters on tunable VCSEL lasing wavelength was studied, and the results show that as the increase of the duty cycle and thickness of sub-wavelength grating, the lasing wavelength will be red shift, while the effect of the grating period on the lasing wavelength is very small. Because of the large tuning range of ISWG-VCSEL, it can reduce business costs and increase the flexibility networks nature and will be very useful in spectrum analysis fields. And the lasing wavelength can be easy designed by changing the grating parameters.