A thermionic electron emission device includes an insulating substrate and one or more lattices located on the insulating substrate. The source of modulated light is modulated in response to a local oscillator and the LAR is activated in response to the modulated light. An oxygen anneal step is subsequently performed to completely convert the rich oxygen containing polysilicon residue into silicon dioxide that can eliminate the conductivity of the polysilicon residue and prevent oxygen encroachment occurring. Also included is a mud ramp that creates a large junk slot from the borehole bottom up the drill bit.