title: Quasi synchronous tuning for grating feedback lasers.
abstract: A general analytical form of the round trip phase shift in grating feedback diode lasers is proposed. Using the new form, it is obvious that the round trip phase shift can be independent of rotation angle in first order approximation when only one restriction condition is met. We call this the quasi synchronous tuning (QST) condition. In the QST region, a considerably large mode hopping free tuning range can be obtained. An adjustment structure with only one freedom is needed to accurately find and locate the quasi synchronous pivot, which is not strictly confined on the grating surface and its extension. It means that the external cavity diode lasers design can be easier and the laser can be more stable and reliable.
authors.affiliation: Center of Time and Frequency Metrology, National Institute of Metrology, Beijing, China.
authors.forename: Erjun
authors.initials: E
authors.lastname: Zang
authors.forename: Shaokai
authors.initials: S
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yu
authors.initials: Y
authors.lastname: Peng
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
authors.forename: Jianping
authors.initials: J
authors.lastname: Cao
authors.forename: Tianchu
authors.initials: T
authors.lastname: Li
authors.forename: Zhanjun
authors.initials: Z
authors.lastname: Fang