sputnik lazer
No, the path of light is not affected by the presence of a magnetic field.
Light itself has oscillating electromagnetic fields, and follows the linear properties of electric and magnetic fields. Linearity means that the fields are simply additive or subtractive, and do not interact with one another. If you add a magnetic field to the existing magnetic field of light, the combined magnetic field will simply be the sum or difference of the two where the external field exists. The orginal field of the light is unchanged, and the original external field is unchanged - the light continues through the external field unchanged. The reach of the external field is also unchanged by the passage of the light.
Gravity does cause light to change direction. If you could create a gravity well, you could bend light with that. Gravity is not a field - it is a warp in the time space continuum (at least that is what Einstein said, and nobody has proven him wrong).
A magnetic field can change the path of a laser beam if it is applied to a material through which the light passes, or from which the light is reflected. The material would have to be one which changes refractive or reflective properties when subjected to a magnetic field, and such materials do exist. They are called magneto-optic materials.