The linewidth of a single frequency laser plays an important role in improving the detection distance of a distributed optical time-domain reflectometer (OTDR). The commonly used linewidth measurement method is the delayed self heterodyne interferometer (DSHI). However, it is usually difficult to calibrate the linewidth of fiber laser (less than 1 kHz) with DSHI, because which requires the optical path difference of interferometer to be far greater than the coherence length. We accurately characterized the laser linewidth based on the sine-cosine optical frequency analysis of the 3×3 coupler Michelson interferometer. First, we accurately and rapidly detected the change of optical frequency under the stable state of laser, and then analyzed and accurately obtained the linewidth through the power spectral density (PSD) of frequency noise. The linewidth of the 1550 nm single frequency fiber laser is accurately detected and with 0.8 kHz, which is close to the technical parameter table with the linewidth of 1 kHz. Our work is important for selecting the light sources in φ-OTDR and other applications and points to a standard and convenient method in the field of the linewidth measuring.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.