Voltage detection apparatus

A voltage detection apparatus, comprising:

• detection means for detecting a strength of an electric field by a voltage applied to a surface of a device to be measured and modulating an electric signal, based on the strength of said electric field;
• light-emitting means for modulating output light, based on said electric signal modulated by said detection means;
• extraction means for extracting a signal component of said output light from said light-emitting means;
• and
• a constant current source for supplying a bias current, wherein said light-emitting means comprises a semiconductor laser which receives said bias current from said constant current source to inductively radiate said output light, and modulates said output light by superposing said signal detected by said detection means on said bias current;
• wherein said detection means comprises a needle-shaped metal electrode inserted in a hollow tube consisting of a non-conductive material, said metal electrode of said detection means and an upper electrode of said semiconductor laser are connected to one electrode of said constant current source, and a lower electrode of said semiconductor laser is connected to the other electrode of said constant current source.

A voltage detection apparatus, comprising:

• detection means for detecting a strength of an electric field by a voltage applied to a surface of a device to be measured and modulating an electric signal, based on the strength of said electric field;
• light-emitting means for modulating output light, based on said electric signal modulated by said detection means;
• extraction means for extracting a signal component of said output light from said light-emitting means;
• and
• a constant current source for supplying a bias current, wherein said light-emitting means comprises a semiconductor laser which receives said bias current from said constant current source to inductively radiate said output light, and modulates said output light by superposing said signal detected by said detection means on said bias current;
• wherein said detection means comprises a dipole-shaped metal electrode, said detection means and an upper electrode of said semiconductor laser are connected to one electrode of said constant current source, and a lower electrode of said semiconductor laser is connected to the other electrode of said constant current source.

A voltage detection apparatus, comprising:

• detection means for detecting a strength of an electric field generated by a voltage applied to a surface of a device to be measured and modulating an electric signal, based on the strength of said electric field;
• light-emitting means for modulating output light, based on said electric signal modulated by said detection means;
• extraction means for extracting a signal component of said output light from said light-emitting means
• placing means for placing the device to be measured;
• and
• three-dimensional position adjustment means for adjusting a relative positional relationship between the device to be measured and said detection means.

A voltage detection apparatus comprising:

• a semiconductor laser for detecting a strength of an electric field generated in a space by a voltage applied to a surface of a device to be measured by bringing a lower electrode thereof close to a surface of the device to be measured, and modulating output light by the detected signal;
• a constant current source for supplying a bias current to said semiconductor laser;
• extraction means for extracting a signal component of the output light from said semiconductor laser;
• and
• light-transmission means for guiding the output light from said semiconductor laser to said extraction means.

A voltage detection apparatus comprising:

• a plurality of two-dimensionally arranged detection means for detecting strengths of an electric field generated in a space by a voltage applied to a surface of a device to be measured;
• a semiconductor laser array, consisting of a plurality of semiconductor lasers corresponding to said plurality of detection electrodes, for modulating output light beams by superposing detected signals obtained from said plurality of detection electrodes on a bias current which is supplied to inductively radiate the output light beams;
• a constant current source for supplying the bias current to said semiconductor laser array;
• extraction means for extracting signal components of the output light beams from said semiconductor lasers of said semiconductor laser array;
• and
• light-transmission means for guiding the output light beams from said semiconductor laser array to said extraction means.