Laser dual-modulation reflection spectrum detection system based on microscope

Abstract

The invention discloses a laser dual-modulation spectrum system based on a microscope. The laser dual-modulation spectrum system comprises a single-mode optical fiber, an imaging amplification system, a semi-transmittance semi-reflection sheet, a laser beam expanding system, a low-frequency chopper, a laser device, a microscope system and a high-frequency chopper. Laser dual-modulation reflection spectrum measurement on a nano material is carried out in the manner that according to a laser dual-modulation working theory, a white light source modulated by the high-frequency chopper serves as detection light after passing through a microscope lighting system; after being subjected to beam expanding, laser modulated by the low-frequency chopper is used as pumping light; the detection light and the pumping light work on the surface of a sample after passing through a same microscope objective; the single-mode optical fiber serving as a field diaphragm is arranged at a secondary amplified image surface; under motor control, bi-dimensional scanning is carried out on a sample surface to acquire a relevant optical signal. The laser dual-modulation spectrum system based on the microscope can be used for carrying out spectrum detection on a nano level region, is capable of eliminating interference of background reflection light effectively and can be applied to measurement on an optical characteristic spectrum in the micro-nano optical field.

Description

technical field [0001] This patent belongs to the field of spectral analysis technology, and specifically relates to a microscope-based laser double-modulation reflection spectrum detection system, which is used for optical characteristic detection of nanoscale materials such as nanobelts and nanowires. Background technique [0002] Nanomaterials refer to materials in which at least one dimension in the three-dimensional space is in the range of nanometer size or composed of them as basic units. Compared with conventional bulk materials, it has many specific properties, such as: quantum size effect, surface effect, quantum tunneling effect, etc., which make the behavior of atoms and electrons in the surface state very different from those in the interior. , resulting in nanomaterials having new optical properties that the same kind of macroscopic materials do not possess. To study the optical properties of nanomaterials, microscopic techniques are needed. In addition, phot...

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Problems solved by technology

However, the laser modulation technology also has certain limitations, because when the laser is periodically incident on the surface of the sample, the fluorescence emitted by the sample itself will have the same carrier frequency, so the detection signal will include the fluorescence background signal at the same time, in order to overcome the laser modulation technology To solve the fluorescence background problem, it is necessary to introduce laser dual modulation technology that can suppress the fluorescence background. By making the reflection spectrum change and the fluorescence background signal have different carrier frequencies, the two signals can be distinguished during the signal extraction process.

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