  Precisely stabilizing laser frequency is crucial for advancing laser
technology and unlocking the full potential of various quantum technologies.
Here, we propose a compact device for stabilizing frequency of a semiconductor
laser through mode coupling effects, which provides enhanced sensitivity. Our
proposed architecture features a main ridge waveguide with a Bragg grating,
flanked by two curved ridge waveguides. This configuration exhibits an optical
phenomenon characterized by a transmission crossing at the wavelength of the
Bragg grating. Using particle swarm optimization strategy and employing
efficient figures of merit, we achieve a high transmission crossing. The
observed asymmetric transmission crossing not only holds the promise for an
efficient and compact on-chip laser frequency stabilizer, but also fosters the
development of novel sensing platforms with heightened sensitivity.
