CN101275867A - a light detector - Google Patents

Abstract

The present invention provides a photodetector, which includes: a photosensor connected to a first electrode and a second electrode of the photosensor; and a first electrode lead and a second electrode lead, the first electrode lead and the second electrode lead One end of the two electrode lead wires is respectively connected to the first electrode and the second electrode, and the other end is used as an output end; the optical sensor is made of metal or alloy material. The photodetector of the present invention can quickly respond to laser pulses with femtosecond pulse widths in ultraviolet or infrared bands, and the width of generated voltage pulses can be less than 0.5 nanoseconds, and the full pulse width is only a few nanoseconds.

Description

a light detector

technical field

The invention relates to a laser detection device, in particular to an infrared or ultraviolet light detector.

Background technique

The detection of laser energy, power, pulse width and waveform is not only very important for laser devices and basic research, but also has a very wide range of uses in military, national defense, agriculture, resource mining, transportation, etc. Laser detector components are mainly supported by semiconductor materials, conventional compound materials, and polymer composite materials that have certain response characteristics to laser light, and their structures and principles are also varied. At present, people have researched and developed various types of laser detectors such as pyroelectric, photoelectric, and pyroelectric. Heteromanganate film and photodetector doped lanthanum manganate film layer, literature [1] PXZhang, WKLee, GYZhang. "Time dependence of laser-induced thermo-electric voltages in La _1-x Ca _x MnO ₃ and YBa ₂ Cu ₃ O _7-δ thin films.” Appl. Phys. Lett., 2002, 81(21): 4026-4028 discloses a pyroelectric laser detector with La _1-x Ca _x MnO ₃ as the photoresponse layer , but the photovoltaic signal of this pyroelectric laser detector originates from the pyroelectric effect caused by the thermal gradient, which limits its response speed as a laser detector. Therefore, although the pyroelectric detector has a wide response range, the response time is relatively slow, mostly on the order of milliseconds or microseconds. Therefore, the exploration of fast-response and high-sensitivity new ultraviolet photodetectors is still one of the research hotspots. Up to now, there have been no reports of using metals or alloys directly in photodetectors.

Contents of the invention

The object of the present invention is to provide a laser detector, which uses metal or alloy as the photosensor (ie photoresponse chip), does not need auxiliary power supply and electronic circuit, and can directly generate photoelectric signal after laser irradiation.

In order to achieve the above purpose, the photodetector provided by the embodiment of the present invention includes:

light sensor;

connecting the first electrode and the second electrode of the light sensor; and

a first electrode lead and a second electrode lead, one end of the first electrode lead and the second electrode lead are respectively connected to the first electrode and the second electrode, and the other end is used as an output end;

The light sensor is made of metal or alloy material.

The light response frequency band of the light sensor is infrared and/or ultraviolet light frequency band.

The invention directly utilizes the photodetector made of metal or alloy, which can detect the energy, power and pulse waveform of the laser, and can quickly respond to the laser pulse with femtosecond pulse width in the ultraviolet or infrared band, and the width of the generated voltage pulse can be less than 0.5 nanoseconds, the full width of the pulse is only a few nanoseconds.

Description of drawings

The drawings described here are used to provide further understanding of the present invention, constitute a part of the application, and do not limit the present invention. In the attached picture:

1 is a schematic structural view of a photodetector made of metal or alloy wires according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of the photodetector structure when the metal or alloy wire in Fig. 1 is in a spiral shape;

Fig. 3 is a schematic diagram of the photodetector structure when the metal or alloy wire in Fig. 1 is in a zigzag shape;

4 is a schematic structural diagram of a photodetector according to another embodiment of the present invention;

FIG. 5 is a diagram of the photovoltaic characteristic signal generated by the photodetector according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments and descriptions of the present invention are used to explain the present invention, but not to limit the present invention.

Example 1

Referring to Fig. 1, the photodetector of the present embodiment comprises: housing (not shown in the figure), photosensor (or claim photoresponse chip) 1, first electrode 2, second electrode 3, first electrode lead 4 and the first Two electrode leads 5. Wherein, the photosensor 1 is made of metal or alloy, and the two connecting ends of the photosensor are respectively connected to the first electrode 2 and the second electrode 3; one end of the first electrode lead 4 and the second electrode lead 5 is respectively connected to the first electrode 2 and the second electrode 3, the other end of the first electrode lead 4 and the second electrode lead 5 is the signal output end; the photosensor 1, the first electrode 2, the second electrode 3, the first electrode lead 4 and the second Electrode lead wire 5 is arranged in described housing, and utilizes coaxial cable joint to draw described output terminal from described housing, and this output terminal can be connected with amplifying circuit (to amplify the photovoltaic characteristic signal that light sensor produces); This output terminal can also be A voltage testing device 6 is connected to detect the photovoltaic signal generated by the sensor.

The light sensor is made of metal or alloy material. The metal may be, for example, copper, gold, silver, aluminum, nickel, chromium, iron, etc., but is not limited thereto. The alloy may, for example, be an alloy comprising one or more of the aforementioned metals. In this embodiment, the shape of the metal or alloy used as the optical sensor 1 is not particularly limited, and may be a metal or alloy sheet, or a metal or alloy wire. For example, when the sensor adopts a metal or alloy wire, the metal or alloy wire can be straight or bent into other shapes, such as rectangle, spiral, zigzag, etc., and the metal or alloy wire can be a root, or a plurality of parallel connections, and the present invention is not limited thereto. 2 and 3 are structural schematic diagrams of photodetectors with spiral and sawtooth sensors, respectively.

In the embodiment of the present invention, the first electrode 2 and the second electrode 3 may be metal (such as gold, silver, platinum, indium, aluminum, etc.) or alloy, or other conductive materials. In the embodiment of the present invention, metal thin films are preferably used as electrodes, and the required electrode thin films can be prepared by chemical vapor deposition, pulsed laser deposition, sputtering, vacuum coating or other thin film deposition methods, and grown on metal or alloy photosensors. connection end.

The first electrode lead 4 and the second electrode lead 5 can adopt conventional metal electrode leads (such as Φ0.2mm copper wire, but not limited thereto), the first electrode lead 4 and the second electrode lead 5 One end can be welded on the first electrode 2 and the second electrode 3 respectively, and the other end is used as an output end.

In the embodiment of the present invention, the shell is a metal or alloy shell to shield external electromagnetic interference.

Using the photodetector as shown in Figure 1, various laser parameters such as laser energy, laser power, and laser pulse waveform can be detected, and the response band of the photosensor is the ultraviolet or infrared band.

For example, metal material electrodes are grown on commonly used straight copper wires (diameter, for example, 0.1 mm to 1 mm, but not limited thereto), and then an ultraviolet or infrared photodetector with the structure shown in Figure 1 is produced . Then select a 350MHZ oscilloscope to connect the two output terminals of the light detector to measure ultraviolet or infrared pulsed laser light. If the infrared femtosecond pulse width pulse laser with a wavelength of 1064nm is used as the probe light, the energy of the single laser pulse is 5 millijoules, the area of the beam is one square centimeter, and the electrode is avoided to shine on the copper wire, as shown in Figure 5. A direct voltage output of about 3.5mV was obtained by measuring with an oscilloscope, that is, the output photovoltaic signal reached ~3.5 millivolts, and the rise time of the photovoltaic signal was <1ns, and the full width at half maximum was ~1ns. At the same time, it should be noted that the rise and half-height width of the photovoltaic signal reach the limit of the oscilloscope. If a faster oscilloscope is used for measurement, the rise time will be shorter, indicating that this detector has the characteristics of fast response.

If the present invention adopts straight wires of materials such as gold, silver, aluminum, nickel, chromium, iron, etc. instead of straight copper wires as optical sensors, the prepared optical detectors can also detect the energy, power, pulse waveform, etc. of laser light, It can respond to laser pulses with femtosecond pulse width in the ultraviolet or infrared band, and the width of the generated voltage pulse can be less than 0.5 nanoseconds, and the full pulse width is only a few nanoseconds.

If the present invention adopts wires of other shapes such as copper, gold, silver, aluminum, nickel, chromium, iron, etc., such as rectangular, spiral or zigzag wires, copper, gold, silver, aluminum, nickel, chromium, iron Metal sheets of other materials are used to replace straight copper wires to prepare photodetectors, which can also detect laser energy, power, pulse waveforms, etc., and can respond to laser pulses with femtosecond pulse widths in the ultraviolet or infrared bands to generate voltage pulses. The width can be less than 0.5 nanoseconds, and the full pulse width is only a few nanoseconds.

If the present invention uses alloy materials instead of the metal material to prepare photodetectors, it can also detect the energy, power, pulse waveform, etc. of the laser, and can respond to laser pulses with femtosecond pulse widths in the ultraviolet or infrared bands to generate voltage pulses with the width of It can be less than 0.5 nanoseconds, and the full pulse width is only a few nanoseconds.

Example 2

This embodiment is still manufactured according to the structure of Embodiment 1, the difference is that a capacitor 7 is connected in parallel between the first electrode lead 4 and the second electrode lead 5, as shown in FIG. 4 . The function of the capacitor is to adjust the RC constant of the photodetector, thereby further improving the response speed of the photodetector. In this embodiment, the size of the capacitor is preferably 0.01pF˜10pF, but it is not limited thereto.

As mentioned above, the photodetector made of metal or alloy materials has a simple structure, and the response bands are ultraviolet and infrared bands. It can respond to laser pulses with a femtosecond pulse width, and the response time is less than 1 nanosecond, and the half-height of the voltage pulse is generated. It is about 1 nanosecond wide and has good fast response characteristics.

The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the detector circuit or manufacturing method of the present invention is modified or equivalently replaced. , and any modification or partial replacement without departing from the spirit and scope of the present invention shall fall within the scope of the claims of the present invention.

Claims (10)

1. A photodetector comprising: light sensor; connecting the first electrode and the second electrode of the light sensor; and a first electrode lead and a second electrode lead, one end of the first electrode lead and the second electrode lead are respectively connected to the first electrode and the second electrode, and the other end is used as an output end; It is characterized by: The light sensor is made of metal or alloy material. 2. The photodetector according to claim 1, characterized in that, the photodetector further comprises a housing; The light sensor, the first electrode, the second electrode, the first lead wire and the second lead wire are arranged in the casing, and the output end is led out from the casing through a coaxial cable connector. 3. The photodetector according to claim 1, wherein the photodetector further comprises: A capacitor connected between the first electrode lead and the second electrode lead. 4. The photodetector according to claim 1, characterized in that: The capacitance is 0.01pF˜10pF. 5. The photodetector according to claim 1, characterized in that: The light response frequency band of the light sensor is infrared and/or ultraviolet light frequency band. 6. The photodetector according to any one of claims 1-5, characterized in that: Said metal means copper, silver, gold, aluminum, nickel, chromium or iron; The alloy refers to an alloy including one or more materials among copper, silver, gold, aluminum, nickel, chromium and iron. 7. The photodetector according to any one of claims 1-5, characterized in that: The light sensor is a metal or alloy wire. 8. The photodetector according to any one of claims 1-5, characterized in that: The metal or alloy wire is straight, helical, rectangular or zigzag. 9. The photodetector according to any one of claims 1-5, characterized in that: The light sensor is a metal or alloy sheet. 10. The photodetector according to any one of claims 1-5, characterized in that: An amplifier circuit is connected between the two leads to amplify the photovoltaic signal generated by the light sensor.

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