Abstract: A miniature, flexible, fiber-optic scanning endoscope for nonlinear optical imaging and spectroscopy. The endoscope uses a tubular piezoelectric actuator for activating a cantilevered optical fiber from which pulsed light produced by a laser source exits and is directed to a target region through a micro-lens. The actuator is activated by two modulated signals that achieve two-dimensional beam scanning in a desired scan pattern. A double-clad optical fiber is employed for delivery of the excitation pulsed light and collection of emitted light received from the target region. The pulsed light travels through a core of the double-clad optical fiber, and the emitted light from the target region is directed into the core and inner cladding of the optical fiber and conveyed to a proximal end, for detection and processing. The emitted light can include multiphoton fluorescence, second harmonic generation light, and spectroscopic information, for use in imaging.

Abstract: An optical fiber for use in fiber optic sensing of a test sample includes a first core and a second core. The second core is generally coaxially disposed within the first core and is sized smaller than the first core. The second core is capable of delivering pulsed laser energy from the laser for nonlinear optical excitation of the test sample. Nonlinear optical feedback signals can then be collected in both the first core and second core for improved detection efficiency relative to conventional single-mode and multi-mode fibers.

Abstract: An optical fiber for use in fiber optic sensing of a test sample includes a first core and a second core. The second core is generally coaxially disposed within the first core and is sized smaller than the first core. The second core is capable of delivering pulsed laser energy from the laser for nonlinear optical excitation of the test sample. Nonlinear optical feedback signals can then be collected in both the first core and second core for improved detection efficiency relative to conventional single-mode and multi-mode fibers.

Abstract: An optical fiber for use in fiber optic sensing of a test sample includes a first core and a second core. The second core is generally coaxially disposed within the first core and is sized smaller than the first core. The second core is capable of delivering pulsed laser energy from the laser for nonlinear optical excitation of the test sample. Nonlinear optical feedback signals can then be collected in both the first core and second core for improved detection efficiency relative to conventional single-mode and multi-mode fibers.

Abstract: An optical fiber for use in fiber optic sensing of a test sample includes a first core and a second core. The second core is generally coaxially disposed within the first core and is sized smaller than the first core. The second core is capable of delivering pulsed laser energy from the laser for nonlinear optical excitation of the test sample. Nonlinear optical feedback signals can then be collected in both the first core and second core for improved detection efficiency relative to conventional single-mode and multi-mode fibers.