JPS5857114A - Converting element to visible wave length for infrared ray - Google Patents

Abstract

PURPOSE:To make an incoherence visible light emit light by excitation of infrared light having about 0.82mum wave length, by using a substance having a fluoride as a base body and allowing trivalent Er ion of specific atomic percent of total cation to contain, as a wave length conversion material. CONSTITUTION:Primary array of semiconductive laser 3 is formed with a semiconductive laser 1 as an infrared light source having an oscillation wave length to 0.82mum consisting of a GaAlAs three-way system together with the same semiconductive laser 2 etc. An infrared light 4 of oscillation output of the semiconductive laser 1 is converged to a small crystal piece 7 of an infrared visible wave-length converting element housed in a vessel 6 through a ''SELFOC '' lens 5. This small piece 7 has YF3, BaY2F8, NaYF4 or LaF3 being a fluoride as a base body and is a wave length conversion material allowing trivalent Er ion of 5-20 atomic percent of total cation to contain and has the composition as BaY1.4Er0.6F3 and is excited by excitation of the infrared light 4 having around 0.82mum wave length to generate red, green or yellow intensive visible light in accordance with the condition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an infrared-visible wavelength conversion element having a novel structure and an apparatus thereof.

Semiconductor lasers made from m-v group compound semiconductors can be directly modulated and have a relatively large oscillation output, and have recently become possible to have short oscillation wavelengths near the visible region and to be configured in an array. As a result, they are increasingly being used not only for high-end applications such as optical communications, which have been used in the past, but also for some so-called low-end applications, such as image applications such as laser printers.

However, it is virtually impossible for semiconductor lasers currently in use using GaAtAs ternary mixed crystals to oscillate in the visible range, where photographic paper has high sensitivity, and in areas close to the so-called visible range, for example, from 750 mμ. When oscillating at short wavelengths and making them visible to the naked eye, the oscillation threshold increases due to the need to use a high kl mixture ratio, and the lifetime and reliability decrease rapidly due to reasons such as sensitivity to humidity. There was a drawback that it deteriorated. For these reasons, attempts to construct a laser printer or the like using a semiconductor laser array that extends into the visible range have not yet become a reality.

In view of the current situation of semiconductor lasers that require short wavelength light, the present invention provides a simple infrared-visible conversion element and device, thereby effectively converting the oscillation light of the semiconductor laser in the infrared region into visible light, especially green light. The object of the present invention is to provide a wavelength conversion element and device capable of converting light into light.

According to the invention, the fluoride YF3 BaY2F
, 3NaYF4 or uLaF3f as a substrate and containing trivalent Er ions of 5 to 20 atoms of all cations as a wavelength conversion material. An infrared-visible wavelength conversion element that emits coherent visible light and an infrared-visible wavelength conversion device using this element are obtained.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment of the present invention.

The semiconductor laser 1 is made of a GaAtAs ternary system082
It is an infrared light source with an oscillation wavelength in μm, and is used as a semiconductor laser primary array 31r along with similar semiconductor lasers 2 and the like.
, is forming. The oscillation output infrared light 4 of the semiconductor laser 1 is focused through the SELFOC lens 5 onto a small crystal piece 7Vc of an infrared-visible wavelength conversion element housed in a container B. This crystal piece has a composition of BaYl 4Ero6F5 and is excited by infrared light 4 to generate strong visible light of red, green or yellow color depending on the conditions.

The container 6VC is formed with a small hole 8 that allows the excitation infrared light to enter in the direction of incidence.

On the other hand, it is transparent to visible light in the direction in which visible light is extracted, and reflective to infrared light of 082 μm, which is the excitation light, and if possible, around 1.0 μm2.
A window 9 consisting of a chromatic filter is provided. The inner surface of the container wall is reflective. Therefore, when viewed from the side of the window 9, the entire window appears to glow green, for example, when the excitation infrared light is incident.

A visible light emitting array can be obtained by equipping all the semiconductor lasers 2 and the like constituting the semiconductor laser array 1 with a similar conversion device (not shown in the figure).

In this way, the generation of visible light due to the excitation of infrared light around 0.82 μm can be observed to varying degrees in materials containing trivalent ergium (Er) ions, but it is not efficient. The light emitting material is a fluoride material that can maintain a long excited state lifetime as a substrate.

That is, it was obtained by using YF3 BaY2 FB NaYF4 or LaF5f and containing about 5 to 20 atoms of Erpira (Er) ions out of all the cations.

Regarding the latter content, favorable results were obtained, particularly in the vicinity of 10 atoms. In addition, it is possible to generate visible light emission by using a structure in which a phosphor is coated on a flat plate instead of a structure in which small crystal pieces are stored in an internally reflective container, but the visible light emission intensity is usually too small to be practical. I don't like it from a certain point of view. Therefore, by using a single crystal piece and adopting a so-called optical confinement structure.

Wavelength conversion efficiency is significantly improved. In one example, energy conversion efficiencies of up to 15% can be achieved.

Next, nine principles of the present invention will be explained in order to further clarify the features of the present invention. 1. Figure 2 is an energy level diagram of a trivalent erbium ion, and the vertical axis is graduated in wavenumber units. When infrared light of 082 μm is incident, a transition shown by a occurs, and the excited level b is reached.

If the concentration of erbium ions is high, the excitation energy will be transferred to the neighboring erbium ions 17i.

In this way, excitation energy is transferred through the crystal. Moreover, when both adjacent erbium ions are in the excited state shown in b, energy is exchanged between them, and by chance c(!-d), some of the energy levels are almost equal in distance. The erbium ions are raised to the e level, which is the green emission level, and strong green emission is thus observed.The red emission is thought to be caused by a slightly more complicated mechanism.

The first application of such a wavelength conversion device is, for example, laser printers that take advantage of the controllability and short wavelength light emission of semiconductor lasers, but it can also be used in many other fields related to displays and information processing. It has a purpose. However, the time response is 10m5ec
Or even longer.

It is not well suited for applications requiring high speed, such as flying spot scanners.

By using such an infrared-visible wavelength conversion device, the lifespan and body axis properties are much improved compared to the conventionally thought short wavelength oscillation semiconductor laser, and it is also possible to emit light at a short wavelength. . Of course, the luminescence obtained in this way.

In terms of brightness, this cannot be achieved with light emitting diodes.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing the energy level of a hexavalent erbium ion used in the infrared-visible wavelength conversion element of the present invention on a wave number scale of 1. . Explanation of symbols: 1 and 2 are semiconductor lasers, 3 is a semiconductor laser array, 4 is an output light, 5 is a self-occurring laser, 6 is a container, 7 is a BaY j 4 Er06 F5 crystal piece,
8 is a small hole for excitation light incidence, 9 is a dichroic filter, and a is 0.
The transition due to excitation by 82 μm light, b indicates the excited state corresponding to a, 4, C and dfl possible transitions, and e indicates the green emission level, respectively.

Claims (1)

[Claims] 1.7 fluoride YF3 BaY2 FB Na
YF4 or hLaF3 t-base material containing 5 to 20 trivalent Er ions of all cations is used as a wavelength conversion material, and by excitation with infrared light having a wavelength of around 0.82 μm. An infrared-visible wavelength conversion element that emits incoherent visible light. 2. The source of infrared light around 0.82 μm is GaAtAs.
An infrared-visible wavelength conversion element having a claimed range of 1°, which is a semiconductor laser made of a material. 3.7 fluoride YF3. BaY2F8. NaYF4
Alternatively, a substance made of IdLaF5 as a base and containing trivalent Er ions of 5 to 20 atoms of all cations is used as a wavelength conversion material, and incoherent conversion is performed by excitation of infrared light having a wavelength of around 0.82 μm. An infrared-visible wavelength conversion element that emits visible light is installed at two locations on a wall whose inner surface is reflective, and a window that allows the infrared light to enter the wall, and a window that is reflective at least for the infrared light, but the In a container equipped with a dichroic filter window that is transparent to visible light,
An infrared-visible wavelength conversion device that accommodates the emitted visible light so that it can be seen from the side of a chromatic filter window.