Underwater laser-guided discharge

A method for producing a laser-guided underwater electrical discharge, comprising:

• at time t1, firing a laser pulse having a power P greater than a critical power Pcrit past a first electrode in a body of water, the electrode being connected to an external power supply,
• the power P and a focusing of the laser pulse being configured to cause the laser pulse to generate an optical filament defining a desired electrical discharge path in the water, the power P of the laser pulse further being configured to cause the optical filament to heat a water column coincident with the optical filament and to cause the water column to vaporize and expand at time t2>t1 to form a vapor column around the optical filament, the vapor column having a greater conductivity than the water surrounding the vapor column;
• and
• using the external power supply, producing a driving electric field which generates an electrical discharge at time t3>t2;
• wherein the optical filament is configured to guide the electrical discharge through the vapor column along the desired electrical discharge path defined by the optical filament.

A method for producing a laser-guided underwater electrical discharge, comprising:

• at time t1, firing a first laser pulse having a power P1 greater than a critical power Pcrit (liquid water) past a first electrode in a body of water, the electrode being connected to an external power supply,
• the power P1 and a focusing of the first laser pulse being configured to cause the first laser pulse to generate a first optical filament in the water, the power P1 of the first laser pulse being further configured to cause the optical filament to heat a water column coincident with the first optical filament and to cause the water column to vaporize and expand at time t2>t1 to form a vapor column surrounding the first optical filament;
• at time t3>t2, firing a second laser pulse having a power P2 greater than a critical power level Pcrit(water vapor) through the vapor column, the power P2 and a focusing of the second laser pulse being configured to cause the second laser pulse to generate a second optical filament defining a desired electrical discharge path within the vapor column, wherein the second optical filament forms a laser-ionized conductive channel through the vapor column along the desired electrical discharge path;
• and
• using the external power supply, producing a driving electric field which generates an electrical discharge at time t4>t3;
• wherein the second optical filament is configured to guide the electrical discharge through the laser-ionized channel along the desired electrical discharge path defined by the second optical filament.

A method for producing a laser-guided electrical discharge in a liquid, comprising:

• at time t1, firing a laser pulse having a power P greater than a critical power Pcrit past a first electrode in a liquid, the electrode being connected to an external power supply,
• the power P and a focusing of the laser pulse being configured to cause the laser pulse to generate an optical filament defining a desired electrical discharge path in the liquid, wherein the optical filament forms a laser-ionized channel through the liquid along the desired electrical discharge path, the laser-ionized channel having a greater conductivity than the surrounding liquid;
• and
• using the external power supply, producing a driving electric field which generates an electrical discharge at time t2>t1;
• wherein the optical filament is configured to guide the electrical discharge through the laser-ionized channel along the desired electrical discharge path defined by the optical filament.

A method for producing a laser-guided electrical discharge in a liquid, comprising:

• at time t1, firing a laser pulse having a power P greater than a critical power level Pcrit past a first electrode in a liquid, the electrode being connected to an external power supply,
• the power P and a focusing of the laser pulse being configured to cause the laser pulse to generate an optical filament defining a desired electrical discharge path in the liquid, the power P of the laser pulse further being configured to cause the optical filament to heat a liquid column coincident with the optical filament, and to cause the liquid column to vaporize and expand at time t2>t1 to form a vapor column around the optical filament, the vapor column having a higher conductivity than the surrounding liquid;
• and
• using the external power supply, producing a driving electric field which generates an electrical discharge at time t3>t2;
• wherein the optical filament is configured to guide the electrical discharge through the vapor column along the desired electrical discharge path defined by the optical filament.

A method for producing a laser-guided electrical discharge in a liquid, comprising:

• at time t1, firing a first laser pulse having a power P1 greater than a critical power Pcrit(liquid) past a first electrode in a liquid, the electrode being connected to an external power supply,
• the power P1 and a focusing of the first laser pulse being configured to cause the first laser pulse to generate a first optical filament in the water, the power P1 of the first laser pulse being further configured to cause the optical filament to heat a liquid column coincident with the first optical filament, and to cause the liquid column to vaporize and expand at time t2>t1 to form a vapor column surrounding the first optical filament;
• at time t3>t2, firing a second laser pulse having a power P2 greater than a critical power level Pcrit(vapor) through the vapor column, the power P2 and a focusing of the second laser pulse being configured to cause the second laser pulse to generate a second optical filament, the second optical filament defining a desired electrical discharge path within the vapor column, wherein the second optical filament forms a laser-ionized conductive channel through the vapor column along the desired electrical discharge path;
• and
• using the external power supply, producing a driving electric field which generates an electrical discharge at time t4>t3;
• wherein the second optical filament is configured to guide the electrical discharge through the conductive channel along the desired electrical discharge path defined by the second optical filament.