JPH0465336B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a laser light source, a laser light beam from the laser light source whose path is bent by 90° using a semi-transparent mirror, and a sample is irradiated through an objective lens, and the laser light irradiation path is bent by 90°. An optical microscope that collects the Raman scattered light generated from the sample with the objective lens and further extracts it in the direction of the optical axis formed by the sample and the objective lens through the semi-transparent mirror, and spectroscopy the Raman scattered light extracted from the optical microscope. , a laser Raman microprobe consisting of a Raman spectrophotometer for detection.

In the laser Raman microprobe, which uses a conventional optical microscope to irradiate laser light and focus Raman scattered light, the laser light is bent in a 90° direction with a semi-transparent mirror, and then irradiated onto the sample through an objective lens. Because the structure is such that the Raman scattered light is collected and extracted through a semi-transparent mirror, the laser reflected light from the sample and the Raman scattered light pass through the same optical path. Therefore, in order to monitor changes in the state of the sample and shifts in the laser irradiation point, a portion of the laser reflected light and Raman scattered light extracted through the semi-transparent mirror is split using a beam splitter, etc., and then taken out using a microscope using a projector, TV camera, etc. The image is observed, but since the amount of Raman scattered light introduced into the Raman spectrophotometer is reduced by the amount divided for monitoring, there is a drawback that detection sensitivity is reduced. In addition, since the laser reflected light is simultaneously introduced into the Raman spectrophotometer through the same optical path as the Raman scattered light, it becomes stray light within the spectrophotometer, interfering with Raman scattered light measurements, especially in the low wavenumber region near the laser wavelength. However, there were significant drawbacks.

An object of the present invention is to eliminate the drawbacks of the prior art described above, to constantly monitor the state of a sample with little loss of Raman scattered light during Raman scattered light measurement, and to
An object of the present invention is to provide a laser Raman microprobe that can reduce stray light within a spectrophotometer based on laser reflected light.

In order to achieve the above object, the laser Raman microprobe of the type mentioned at the beginning according to the present invention is provided with a laser Raman microprobe of the type mentioned at the beginning, which is arranged behind a semi-transparent mirror on the optical axis formed by the sample and the objective lens, and which forms a predetermined angle with respect to the optical axis. It consists of a dichroic mirror that transmits only the laser oscillation wavelength and reflects light with a wavelength longer than the laser oscillation wavelength, and a microscope image monitor at the laser wavelength that is provided behind the dichroic mirror. The main point is to be equipped with a sample monitor. That is, in the present invention, the laser reflected light and the Raman scattered light are collected by an objective lens and taken out through a semi-transparent mirror.
By changing the path of the Raman scattered light using a mirror, the Raman scattered light is divided and taken out separately, and the state of the sample is observed during the Raman scattered light measurement using a microscope image monitor at the laser wavelength placed on the laser reflected light optical path. To efficiently introduce Raman scattered light without mixing reflected light into a spectrophotometer.

Hereinafter, the present invention will be explained in more detail using examples with reference to the accompanying drawings, but these are merely illustrative and it is understood that various improvements and modifications may be made without going beyond the scope of the present invention. Of course.

In FIG. 1, a laser beam 1 for excitation of Raman scattered light enters a semi-transparent mirror 3 of a microscope through a condensing lens 2. The laser beam is bent by 90 degrees with respect to the incident direction by the semi-transparent mirror 3 and is focused onto the sample 5 by the objective lens 4. The laser reflected light 6 and the Raman scattered light 7 generated from the sample 5 are focused by the objective lens 4 and passed through the semi-transparent mirror 3 so that they form an angle of 45° with respect to the optical axis formed by the objective lens 4 and the semi-transparent mirror 3. The light is incident on a dichroic mirror 8 located at . Due to the characteristics of the dichroic mirror 8, the transmitted laser reflected light passes through a neutral density filter 9 and a condensing lens 10, and enters a microscope image monitor 11 using laser reflected light to monitor the state of the sample. Furthermore, due to the characteristics of the dichroic mirror 8, the Raman scattered light is bent at 90 degrees with respect to the optical axis formed by the objective lens 4 and the semi-transparent mirror 3, and is focused onto the spectrophotometer entrance slit 13 through the condensing lens 12. Image.

With this configuration, the loss of Raman scattered light can be reduced even when the sample condition is simultaneously monitored during Raman scattered light measurement using a laser, Raman, or microprobe using a microscope. This has the effect of eliminating laser reflected light that causes stray light within the photometer.

As explained above, according to the present invention, it is possible to monitor the state of the sample during measurement without impairing the detection sensitivity of the sample, and it is possible to quickly find out changes in the state of the sample, shifts in the irradiation point, etc. This method has the advantage of being sensitive and easy to measure Raman scattered light in a low wavenumber region close to the laser wavelength.

[Brief explanation of the drawing]

The figure is a configuration diagram schematically showing a laser Raman microprobe according to the present invention. DESCRIPTION OF SYMBOLS 1...Raman scattered light excitation laser beam, 2...Condensing lens, 3...Semi-transparent mirror, 4...Objective lens, 5
... Sample, 6 ... Laser reflected light, 7 ... Raman scattered light, 8 ... Dichroic mirror, 9 ... Attenuation filter, 10 ... Condenser lens, 11 ... Microscope image monitor using laser reflected light , 12...Condensing lens, 13...Spectrophotometer entrance slit.

Claims (1)

[Claims] 1. A laser light source and the path of the laser light emitted from the laser light source are bent by 90° using a semi-transparent mirror, and the sample is irradiated through the objective lens, and the Raman scattered light generated from the sample by the laser light irradiation is an optical microscope that collects light with the objective lens and further extracts the light in the direction of the optical axis formed by the sample and the objective lens through the semi-transparent mirror;
In a laser Raman microprobe consisting of a Raman spectrophotometer for spectroscopy and detection of Raman scattered light extracted from the optical microscope, the optical axis is located behind the semi-transparent mirror on the optical axis formed by the sample and the objective lens. provided at a predetermined angle with respect to
a dichroic mirror that transmits only the laser oscillation wavelength and reflects light with a longer wavelength than the laser oscillation wavelength toward the Raman spectrophotometer; A laser Raman microprobe characterized by comprising a sample monitor consisting of a microscope image monitor.