Optical waveguide probe and optical system and atomic force microscope using the optical waveguide probe

An optical system for observing a surface shape of a sample by utilizing interatomic force and applying light to or detecting light from the sample, the optical system comprising:

• an optical waveguide probe for applying light to or detecting light from a sample, the optical waveguide probe having a substrate comprised of a piezoelectric element and supported for displacement relative to a surface of a sample due to elastic distortion of the substrate by application of a force thereto and an optical waveguide disposed in the substrate and having a first optical waveguide portion and a second optical waveguide portion disposed generally perpendicular to the first optical waveguide portion;
• vibrating means for vibrating the piezoelectric element to vibrate the optical waveguide probe in a direction generally perpendicular to the surface of the sample at a resonance frequency;
• detecting means for detecting a variation in a resonance frequency of the piezoelectric element resulting from an interatomic force between a tip of the optical waveguide probe and the surface of the sample;
• and
• control means for maintaining a constant interval between the tip of the optical waveguide probe and the surface of the sample based on a detection signal output from the detecting means;
• wherein prior to vibration of the piezoelectric element by the vibrating means to vibrate the optical waveguide probe, the first optical waveguide portion is disposed generally parallel to the sample surface and the second optical waveguide portion is disposed generally perpendicular to the sample surface, and, upon vibration of the piezoelectric element by the vibrating means during application of light to or detection of light from the sample surface by the optical waveguide probe, the optical waveguide probe is vibrated in a direction generally perpendicular to the sample surface.

An optical waveguide probe comprising:

• a cantilever having a longitudinal axis, a fixed end and a free end, the free end being elastically displaceable by application of a force to the cantilever;
• a probe disposed on the free end of the cantilever for undergoing displacement in a direction generally perpendicular to a surface of a sample during elastic displacement of the cantilever, the probe extending in a direction generally perpendicular to the longitudinal axis of the cantilever;
• and
• an optical waveguide disposed in the cantilever and extending from the fixed end of the cantilever to the probe for transmitting light applied to or detected from the surface of the sample, the optical waveguide having a first optical waveguide portion extending generally along the longitudinal axis of the cantilever and a second optical waveguide portion extending generally in the direction of extension of the probe.

An optical system for observing a surface shape of a sample by utilizing interatomic force and applying light to or detecting light from the sample, the optical system comprising:

• an optical waveguide probe comprising a cantilever having a tip disposed on a free end of the cantilever and extending in a direction generally perpendicular to a longitudinal axis of the cantilever, and an optical waveguide disposed in the cantilever for transmitting light applied to or detected from the surface of the sample, the cantilever being comprised of a piezoelectric material, and the optical waveguide having a first optical waveguide portion extending generally along the longitudinal axis of the cantilever and a second optical waveguide portion extending generally in the direction of extension of the tip;
• a vibrating device for vibrating the cantilever to vibrate the optical waveguide probe in a direction generally perpendicular to the surface of the sample at a resonance frequency;
• a detecting device for detecting a variation in a resonance frequency of the cantilever resulting from an interatomic force between the tip of the cantilever and the surface of the sample;
• and
• a control device for maintaining a constant interval between the tip of the cantilever and the surface of the sample based on a detection signal output from the detecting device.