I think then pulse beams are way to go,

instead continuous beams.

As it is disconnected from the source blasting the laser.

 

If the pulse beams are at an angle,

that propels the ship forward,

and synched.

But not strong enough to go reach all the way to the other side of the tunnel it is shooting at.

So short in distance but frequent, constant,

 

then that is singular direction,

and will not stop the motion of the ship by accidentally pushing it to the sides of the tunnel.

 

Kind of like a gas burner. but heading toward one direction as a ring segment of the tunnel.