Continuous phase modulation technology based on grating period interval for high grating coupling coefficient and precise wavelength control

A novel, to the best of our knowledge, grating modulation technique for distributed feedback laser arrays is proposed and demonstrated. This method modifies the initial phase within each grating period, applying a total phase shift that increments in an arithmetic progression, realizing laser arrays with channel spacings of 0.493 nm, 0.949 nm, and 1.956 nm. This method maintains a coupling coefficient comparable to traditional uniform grating structures. Furthermore, the continuous phase modulation enhances the stability of the lasing wavelength of the primary mode, reducing sensitivity to fabrication errors. This improved tolerance to manufacturing inaccuracies represents a significant technological advancement, making this approach highly promising for applications requiring precise and stable wavelength control.