EP-4741782-A1 - LIGHT SOURCE DEVICE

EP4741782A1EP 4741782 A1EP4741782 A1EP 4741782A1EP-4741782-A1

Abstract

A light source apparatus according to an embodiment of the present invention is a light source apparatus that generates wavelength-swept light and includes a pulse light source, a pulse stretcher, and a ventilator. The pulse light source generates pulsed light including a continuous spectrum. The pulse stretcher is configured to lengthen the pulsed light on a time axis and generate the wavelength-swept light. The ventilator supplies air to the pulse stretcher. Accordingly, it becomes possible to suppress a temperature change of the pulse stretcher, and it becomes possible to stably output the wavelength-swept light.

Inventors

NAGASHIMA, TOSHIKAZU

Assignees

Ushio Denki Kabushiki Kaisha

Dates

Publication Date: 20260513
Application Date: 20240702

Claims (20)

A light source apparatus that generates wavelength-swept light, comprising: a pulse light source that generates pulsed light including a continuous spectrum; a pulse stretcher configured to lengthen the pulsed light on a time axis and generate the wavelength-swept light; and a ventilator that supplies air to the pulse stretcher.
The light source apparatus according to claim 1, further comprising a housing portion that includes an inlet for allowing the air to flow in and an outlet for allowing the air to flow out and houses the pulse stretcher in an inner space, wherein the ventilator supplies the air to the inner space through the inlet.
The light source apparatus according to claim 2, wherein the housing portion houses the pulse light source in the inner space.
The light source apparatus according to claim 3, wherein the pulse stretcher is arranged upstream of the pulse light source with respect to a flow path of the air flowing in from the inlet.
The light source apparatus according to claim 3, wherein the inner space of the housing portion has a multi-layer structure constituted by a plurality of layers, each of the pulse light source and the pulse stretcher is arranged in any one of the plurality of layers, and the ventilator supplies the air to the layer where the pulse stretcher is arranged.
The light source apparatus according to claim 5, wherein each of the pulse light source and the pulse stretcher is arranged in a different layer of the plurality of layers.
The light source apparatus according to claim 6, wherein the layer where the pulse light source is arranged and the layer where the pulse stretcher is arranged are spatially continuous in the plurality of layers, and the ventilator supplies the air to the layer where the pulse stretcher is arranged or the layer where the pulse light source is arranged.
The light source apparatus according to claim 5, wherein the multi-layer structure is a structure in which the plurality of layers is stacked in a height direction of the light source apparatus.
The light source apparatus according to claim 2, wherein the inlet is configured to be a position higher than the outlet in the height direction of the light source apparatus.
The light source apparatus according to claim 2, wherein the housing portion includes an uppermost surface that constitutes a top surface of an uppermost layer of the plurality of layers, the uppermost layer being located at a highest position, the inlet is configured in the uppermost surface, and the ventilator supplies the air downwards in the height direction through the inlet.
The light source apparatus according to claim 10, wherein the ventilator is configured in the uppermost surface.
The light source apparatus according to claim 10, wherein the pulse stretcher is arranged in the uppermost layer, the pulse light source is arranged in a layer directly below the uppermost layer, and the uppermost layer and the layer directly below the uppermost layer are spatially continuous.
The light source apparatus according to claim 2, further comprising an air conditioner that generates control air whose temperature is controlled, wherein the ventilator supplies the control air to the pulse stretcher.
The light source apparatus according to claim 13, wherein the inner space of the housing portion has a multi-layer structure constituted by a plurality of layers, and each of the pulse light source, the pulse stretcher, and the air conditioner is arranged in a different layer of the plurality of layers.
The light source apparatus according to claim 14, wherein the multi-layer structure is a structure in which the plurality of layers is stacked in a height direction of the light source apparatus, and the air conditioner is arranged in a layer lower than the pulse light source and the pulse stretcher in the height direction of the light source apparatus.
The light source apparatus according to claim 13, wherein the air conditioner includes a temperature sensor provided in vicinity of the inlet.
The light source apparatus according to claim 16, wherein the temperature sensor is arranged at a position closer to the pulse stretcher than to the pulse light source.
The light source apparatus according to claim 2, wherein the inner space of the housing portion is configured as a thermal insulation space.
The light source apparatus according to claim 13, wherein the ventilator supplies mixed air of the air flowing out from the outlet and the control air to the pulse stretcher.
The light source apparatus according to claim 19, wherein the ventilator has an airflow larger than an airflow of the air conditioner.

Description

Technical Field The present invention relates to a light source apparatus. Background Art Spectroscopic analysis is widely used for component analysis or inspection of target objects. In the spectroscopic analysis, irradiation light is radiated to a target object and a spectrum of object light obtained as a result of the irradiation is measured. Then, optical properties such as reflection properties (wavelength dependency) or transmission properties can be obtained on the basis of a relationship between the spectrum of the object light and the spectrum of the irradiation light. A wavelength-swept-type spectroscopic approach is known as one of approaches for measuring optical properties. In a wavelength-swept-type spectrometric instrument, wavelength-swept light whose wavelength changes over time is generated and radiated to an inspection target. The wavelength-swept light is pulses or pulse train with a one-to-one relationship between time and wavelength. A time waveform of light obtained by radiating the wavelength-swept light to the inspection target is detected by a photodetector. The output waveform of the photodetector represents a spectrum with the time axis corresponding to the wavelength. Patent Literatures 1 and 2 have disclosed wavelength-swept-type spectrometers. Citation List Patent Literature Patent Literature 1: Japanese Patent Application Laid-open No. 2020-159971Patent Literature 2: Japanese Patent Application Laid-open No. 2020-159973 Disclosure of Invention Technical Problem It is important for the wavelength-swept-type spectrometer to stably output the wavelength-swept light. In view of the above-mentioned circumstances, it is an objective of the present invention to provide a light source apparatus capable of stably outputting wavelength-swept light. Solution to Problem In order to accomplish the above-mentioned objective, a light source apparatus according to an embodiment of the present invention is a light source apparatus that generates wavelength-swept light and includes a pulse light source, a pulse stretcher, and a ventilator. The pulse light source generates pulsed light including a continuous spectrum. The pulse stretcher is configured to lengthen the pulsed light on a time axis and generate the wavelength-swept light. The ventilator supplies air to the pulse stretcher. In this light source apparatus, the ventilator supplies the air to the pulse stretcher. Accordingly, it becomes possible to suppress a temperature change of the pulse stretcher, and it becomes possible to stably output the wavelength-swept light. The light source apparatus may further include a housing portion that includes an inlet for allowing the air to flow in and an outlet for allowing the air to flow out and houses the pulse stretcher in an inner space. In this case, the ventilator may supply the air to the inner space through the inlet. The housing portion may house the pulse light source in the inner space. The pulse stretcher may be arranged upstream of the pulse light source with respect to a flow path of the air flowing in from the inlet. The inner space of the housing portion may have a multi-layer structure constituted by a plurality of layers. In this case, each of the pulse light source and the pulse stretcher may be arranged in any one of the plurality of layers. Moreover, the ventilator may supply the air to the layer where the pulse stretcher is arranged. Each of the pulse light source and the pulse stretcher may be arranged in a different layer of the plurality of layers. The layer where the pulse light source is arranged and the layer where the pulse stretcher is arranged may be spatially continuous in the plurality of layers. In this case, the ventilator may supply the air to the layer where the pulse stretcher is arranged or the layer where the pulse light source is arranged. The multi-layer structure may be a structure in which the plurality of layers is stacked in a height direction of the light source apparatus. The inlet may be configured to be a position higher than the outlet in the height direction of the light source apparatus. The housing portion may include an uppermost surface that constitutes a top surface of an uppermost layer of the plurality of layers, the uppermost layer being located at a highest position. In this case, the inlet may be configured in the uppermost surface. Moreover, the ventilator may supply the air downwards in the height direction through the inlet. The ventilator may be configured in the uppermost surface. The pulse stretcher may be arranged in the uppermost layer. In this case, the pulse light source may be arranged in a layer directly below the uppermost layer. Moreover, the uppermost layer and the layer directly below the uppermost layer may be spatially continuous. The light source apparatus may further include an air conditioner that generates control air whose temperature is controlled. In this case, the ventilator may supply the control air to the