  The miniaturization and integration of beam steering devices have
consistently been the focus of the field. Conventional methods alter the
eigenmode of the optical cavity by regulating the refractive index. Due to the
weak nonlinear effect of the optical system, the device must be sufficiently
large to achieve sufficient light modulation. The effective method for
miniaturizing beam steering devices currently in use is based on metasurfaces.
However, this type of device necessitates the input of a laser source, which
precludes the simultaneous generation and control of light in a single device.
Here we propose a miniaturized beam steering device that employs mode selection
between different bound states in the continuum (BIC) states through phase
change material. The device is capable of simultaneously achieving both light
generation and beam steering (33{\deg}) in a single device with a size of only
25 {\mu}m and with a low threshold of 8.9 kW cm-2. Furthermore,it is possible
to achieve a significant degree of dynamic wavelength tunability, with a range
extending up to 296 nm. This method achieves high-efficient regulation of light
properties by dynamically controlling the system's topological charge,
circumventing the problem of weak nonlinearity in traditional methods.
Furthermore, the integration of phase change materials with nanolasers enables
the direct alteration of lasing properties, which provides a novel idea for
dynamic light control. The device process scheme based on phase change
materials is straightforward, direct, and highly compatible, which will be
advantageous for its intended application.
