JPS6297245A - Imaging system - Google Patents

Abstract

PURPOSE:To improve the spatial resolution of an image by measuring are recording the amplitude and the phase of wave such as heat wave, distortion wave or resilient wave occurring on the surface of a sample optically, electrically and thermally while reconstructing the waveface of the produced wave. CONSTITUTION:Laser light 1 is modulated to scan the surface of a sample 5 by means of a scanning mechanism 3. The light collected through a lens 4 to the point P is absorbed to produce thermal wave and acoustic wave in the sample 5 which is propagated. Reflection light caused by a defect is collected to the point Q and detected through a photo detector 7, thus the amplitude and the phase of the wave are measured, constructing a spatial hologram then it is Fourier converted and displayed onto a display 15. Thus a continuous modulating microscope imaging apparatus or a photo-acoustic microscope employing image processing method is formed. Consequently, when applying the side looking rader technology, the sample structure can be viewed non- destructively with high resolution.

Description

Detailed Description of the Invention The present invention utilizes differences in optical, thermal, and acoustic properties of the surface and interior of a sample, such as an ultrasound microscope, a photoacoustic microscope, an electron beam ultrasound microscope, etc. The imaging method of the microscope device measures various image information during the process. In each of the above-mentioned conventional microscope devices, in order to obtain information in the depth direction of the sample, the spatial resolution of the sample surface had to be sacrificed. These conventional microscope devices mainly use continuous wave modulation, and these information detection methods detect information in the form of integrating signals generated from the entire front or back surface of the sample using piezoelectric elements, microphones, etc. be. Furthermore, in the above-mentioned microscope apparatus that uses pulses, it is necessary to use a relatively high-output laser, and there is a risk of destroying the sample. This invention applies the side-looking radar technology used in microwave radars to the field of microscopy, thereby making use of differences in optical, thermal, and acoustic properties to non-destructively improve the surface of a sample. The purpose is to visualize the internal structure. For this purpose, single or multiple transmission points are used to generate waves on and inside the sample using light, electron beams, or ultrasound, or electrical signals are generated by detecting waves optically, acoustically, or thermally. Create a single or multiple reception points to convert the signal into a signal, record the amplitude and phase of the wave while moving these points, spatially construct a hologram from the electrically recorded signals, and convert this into an electrical signal. Fourier transform is performed either physically or optically to obtain an image with better spatial resolution.

An embodiment in which the present invention is implemented as a photoacoustic microscope will be described below with reference to the drawings.

1 is a laser used to irradiate the sample, and its light is modulated by a modulator 2 and scanned over the surface of the sample 5 by a scanning mechanism 3 such as a scanner. A thermal wave and an acoustic wave are generated on the sample surface by absorption of the light focused on the point P by the lens 4, and propagate. If there is a defect or the like inside the sample, the reflection from it will reach the front or back surface of the sample again.

The light from the probe laser 6 is focused on a point Q on the front surface (or back surface) of the probe laser 6 . The light reflected on the sample surface is detected by a photodetector 7 using a method such as heterodyne, and is detected by a signal converter of two or more channels using a method such as synchronous detection together with a modulated signal. After the signal is processed and recorded in both amplitude and phase components, it is displayed as an image on the display 15 based on the position information of point P by the driver signal of the scanner.

In addition, although the laser for sample irradiation is scanned and modulated in the figure, the laser for probe may be scanned and modulated conversely.

As explained above, the present invention has the effect of dramatically improving the spatial resolution of various conventional microscope devices that utilize acoustic waves.

Note that the embodiments of this invention include the following.

(a) Various types of continuous wave modulation type microscopes (ultrasonic microscopes, photoacoustic microscopes, electron beam ultrasound microscopes, microscopes using ion beams, etc.) that use the above-mentioned image processing methods, and imaging devices.

(b) Imaging devices using various pulse modulation type microscopes (ultrasonic microscopes, photoacoustic microscopes, electron beam ultrasound microscopes, microscopes using ion beams, etc.) using the above-mentioned image processing methods.

(c) Imaging devices using various Chirb wave modulation type microscopes (ultrasonic microscopes, photoacoustic microscopes, electron beam ultrasound microscopes, microscopes using ion beams, etc.) using the above image processing method.

(d) Using the above image processing method and transmitting ultrasonic waves,
Various devices described in (a) to (c) above, which use various combinations of optical, electrical, or thermal detection methods in the receiving section for excitation methods such as light and electron beams.

(e) The above-mentioned (
Various devices described in (a) to (d).

[Brief explanation of drawings]

FIG. 1 shows an example of the configuration of a photoacoustic microscope H position. l Laser (for sample irradiation), 2 modulators, 3
Scanning mechanism such as scanner, 4 lenses, 5 specimens (
In this example, it is placed on an X-Y stage), 6
DESCRIPTION OF SYMBOLS 10-Blazer, 7 Photodetector, 8 Modulation signal source, 9 Modulation signal converter, IO photodetection signal converter, 11 Electronic computer, 12 Memory, 13
Scanner driver, 14 driver - signal input/output section, 15 display.

Claims (1)

[Claims] 1 An imaging method for measuring image information on the surface and inside of a sample by utilizing differences in optical, thermal, and acoustic properties of minute parts of a solid sample under a microscope, etc. The amplitude and phase of waves and elastic waves generated on the sample surface are measured and recorded optically, electrically, or thermally at one or more detection points, and the wavefront of the generated waves is reconstructed. A video method characterized by improving the spatial resolution of images by performing