CN1295559C - Ultrashort chirp pulse photon crystal optical parameter amplifying device - Google Patents

Abstract

An ultrashort chirped pulse photonic crystal optical parametric amplifier device is characterized in that the core element of the device is a three-dimensional photonic crystal, and the optical elements of the signal light path entering the three-dimensional photonic crystal are signal light source, first pulse generator, light collimating element, polarizing element, first stretcher and coupling element in sequence; the isolator and the beam splitter are located after the three-dimensional photonic crystal, and the optical elements of another pump light path entering the three-dimensional photonic crystal are pump light laser, second pulse generator, polarizer, second stretcher and shaper in the forward direction of the pump light in sequence; the beam splitter and compressor are after the isolator, and the signal light receiving device is after the compressor. The invention has the characteristics of simple structure, easy operation and high pumping efficiency.

Description

Ultrashort Chirped Pulse Photonic Crystal Optical Parametric Amplification Device

technical field

The invention is an ultrashort chirped pulse photonic crystal optical parameter amplification device. The ultra-short chirped pulse wavelength signal light is amplified mainly according to an optical system that changes nonlinearly in a controllable manner.

Background technique

In the prior art, Przemyslaw.P.Markowicz (Przemyslaw.P.Markowicz) and others in the U.S. made a strong increase in three-dimensional photonic crystals to generate third harmonics (Dramatic Enhancement of Third-harmonic Generation in Three-Dimensional photonic crystals)[Physical Review LettersVol.92, No.8(2004)] discusses the theory and characteristics of the third harmonic generated by light in three-dimensional photonic crystals, in order to provide an amplified ultrashort chirped pulse photonic crystal The optical parametric amplification device laid the theoretical foundation.

Contents of the invention

The purpose of the present invention is to provide an ultra-short chirped pulse photonic crystal optical parameter amplification device, which uses the signal light to generate pulse-modulatable signal light through the pulse generator, and performs the nonlinear effect of spreading in the three-dimensional photonic crystal after it is broadened. The wave is amplified, and then the stretched and amplified pulse is compressed to realize the amplification of the ultrashort chirped pulse signal light. The device should have the characteristics of simple structure, easy operation and high pumping efficiency.

Technical solution of the present invention is as follows:

An ultra-short chirped pulse photonic crystal optical parameter amplification device, which is characterized in that the core component of the device is a three-dimensional photonic crystal, and the optical components entering the signal optical path of the three-dimensional photonic crystal are signal light source, first pulse generator in sequence , light collimating element, polarizing element, first stretcher and coupling element; After the isolator and the light splitting element are located at the described three-dimensional photonic crystal, the optical element entering another pump light path of the three-dimensional photonic crystal is along the pump The forward direction of the pump light is the pump light laser, the second pulse generator, the polarizer, the second stretcher and the shaper in turn; after the isolator is the light splitting element and the compressor, and after the compressor is The signal light receiving device, and the pulse width of the pump light pulse entering the three-dimensional photonic crystal is wider than the pulse width of the signal light pulse, and the pump light pulse completely envelopes the signal light pulse.

The signal light source is a laser, and the laser and the pumping laser are fiber solid-state lasers or semiconductor lasers.

The said first pulse generator and the second pulse generator are electro-optic modulated pulse generators.

The polarizing element and polarizer are Nichols prisms, polarizers, or Wollaston prisms. The light collimating element is composed of a semi-convex spherical lens.

The structure of the first stretcher and the second stretcher is the same, mainly composed of a blazed grating, a convex reflector and a concave reflector. Then it is reflected by the concave mirror and output.

The coupling element is composed of micro-optical lenses.

The three-dimensional photonic crystal is formed by arranging several three-dimensional photonic crystal points on a three-dimensional photonic crystal substrate.

The three-dimensional photonic crystal point is composed of doped glass or quartz doped material, the refractive index of the three-dimensional photonic crystal point is greater than that of the three-dimensional photonic crystal substrate, and the doped elements are rare elements such as ytterbium and erbium. The three-dimensional photonic crystal points are in the shape of a sphere, a cube, a cuboid, a rhombus, a polyhedron or a curve; the arrangement of the three-dimensional photonic crystal points is in the shape of a rhombus, a square, a rectangle or a polygon.

The above-mentioned isolator is a magneto-optical isolator.

The above-mentioned light splitting element is a plane transmission grating, or a transmission blazed grating, or a transmission concave grating.

The above-mentioned reflective element is a plane reflector or a concave reflector.

The receiving device is a CCD diode array detector, or a photodiode, or a photomultiplier tube, or a multi-channel board, or an oscilloscope, or a computer.

The shaper is a diaphragm or a lens.

The advantages of the ultrashort chirped pulse photonic crystal optical parameter amplification device of the present invention:

1. Using the ultrashort chirped pulse photonic crystal optical parameter amplification device of the present invention can realize the amplification of ultrashort pulse chirped wavelength signal light;

2. High pump efficiency.

Description of drawings

Fig. 1 is a structural diagram of the best embodiment of the ultrashort chirped pulse photonic crystal optical parametric amplification device of the present invention.

FIG. 2 is a schematic structural diagram of the stretcher 5 in FIG. 1 .

Fig. 3 is a schematic diagram of the A_A section structure in Fig. 1 .

Fig. 4 is a schematic diagram of the B_B section structure in Fig. 1 .

FIG. 5 is a schematic structural diagram of the compressor 10 in FIG. 1 .

FIG. 6 is a schematic structural diagram of the second stretcher 13 in FIG. 1 .

In the figure: 1-signal light source 2-first pulse generator 3-light collimation element 4-polarization element 5-first stretcher 501-blazed grating 502-convex reflector 503-concave reflector 6-coupling element 7 -Three-dimensional photonic crystal 701-Three-dimensional photonic crystal substrate 702-Three-dimensional photonic crystal point 8-Isolator 9-Splitting element 10-Compressor 1001-Concave blazed grating 1002-Concave mirror 11-Receiving device 12-Shaper 13-Part Two stretchers 1301-blazed grating 1302-convex mirror 303, concave mirror 14-polarizer 15-second pulse generator 16-pump laser

Detailed ways:

First please refer to Fig. 1, Fig. 1 is the structure diagram of the best embodiment of the ultrashort chirped pulse photonic crystal optical parameter amplification device of the present invention, as can be seen from the figure, the ultrashort chirped pulse photonic crystal optical parameter amplification device of the present invention comprises, The core element is the three-dimensional photonic crystal 7, the isolator 8 and the light splitting element 9 are located behind the three-dimensional photonic crystal 7, the coupling element 6, the stretcher 5 and the polarizing element 4 are placed before the three-dimensional crystal photonic 7, and the collimator 3 is placed Before the polarizing element 4, placed before the incident surface of the collimated light element 3 are the pulse generator 2 and the signal light source 1, and the other optical element placed on the side of the three-dimensional photonic crystal 7 is the shaper 12, and the stretcher 13 is located at the shaper Before the polarizer 12, the polarizer 14 is located before the stretcher 13, before the polarizer 14 is a pulse generator 15 and a pump laser 16, after the isolator 8 is a splitting element 9 and a compressor 10, and after the compressor 10 is amplified The signal light receiving device 11.

Said signal light source 1 is a laser, which can be a fiber-optic solid-state laser or a semiconductor laser, and the pump light laser 16 is a laser diode. The light emitted by the signal light source 1 is incident on the pulse generator 2 to generate pulsed signal light and enters the collimated light element. 3. The pulsed signal light emitted by the collimated optical element 3 is polarized by the polarizing element 4 to become linearly polarized light, and the linearly polarized light is incident on the stretcher 5 to be stretched, and the stretched pulsed signal light is incident on the coupling element 6 Above, the light coupled by the coupling element 6 is injected into the three-dimensional photonic crystal 7, and the pumping light is emitted by the laser 16, the pulsed pumping light is generated by the pulse pulse generator 15, and then enters the polarizer 14 to be polarized into linearly polarized light, and then After being widened by the stretcher 13, it enters the shaper 12 to form the required spot shape, and then enters the three-dimensional photonic crystal 7 from the side. The pump light and the signal light are coupled and amplified in the three-dimensional photonic crystal, and then enter the light splitter through the isolator 8. The element 9 and the light splitting element 9 separate the idle light and send the amplified signal light into the compressor 10. The compressor 10 compresses the signal light into ultrashort pulse light and then enters the receiving device 11 of the signal light.

The signal light source 1 and the pumping light source 16 are fiber solid lasers or semiconductor lasers.

Said first pulse generator 2 and second pulse generator 15 are electro-optic modulated pulse generators.

Said polarizing element 4 and polarizer 14 are Nichols prisms, polarizers, or Wollaston prisms.

Said collimating light element 3 is made of semi-convex spherical lens.

The stretcher 5 mainly includes a blazed grating 501 , a convex reflector 502 and a concave reflector 503 , as shown in FIG. 2 .

Said coupling element 6 is formed by micro-optical lenses.

Said three-dimensional photonic crystal 7 is made of glass or quartz. The three-dimensional photonic crystal cross section is shown in Figures 3 and 4. On the three-dimensional photonic crystal substrate 701 is a three-dimensional photonic crystal point 702, and the three-dimensional photonic crystal point 702 It is spherical, cubic, cuboid, rhombus, polyhedral and curved; the arrangement between 702 is rhombus, square, rectangle and polygon. The three-dimensional photonic crystal point 702 is made of doped glass or quartz doped material. The refractive index of the three-dimensional photonic crystal point 702 is higher than that of the three-dimensional photonic crystal substrate 701. The doped elements are rare elements such as ytterbium and erbium.

Said light splitting element 9 is made of a plane transmission grating, or a transmission blazed grating, or a transmission concave grating.

The compressor 10 mainly includes a concave blazed grating 1001 and a concave mirror 1002, as shown in FIG. 5 .

Said receiving device 11 is a CCD diode array detector, or a photodiode, or a photomultiplier tube, or a multi-channel board, or an oscilloscope, or a computer.

Said shaper 12 is made of diaphragm and lens.

The second stretcher 13 on the pump light path mainly includes a blazed grating 1301 , a convex reflector 1302 and a concave reflector 1303 , as shown in FIG. 6 .

The working process of the ultra-short chirped pulse photonic crystal optical parameter amplification device of the present invention is: when the signal light is generated by the pulse generator 2, the pulse signal light is adjusted to parallel light by the collimator light element 3, and then enters the polarizing element 4 to become parallel light. Polarized light, the parallel polarized light is stretched by the first stretcher 5, and the stretched pulse has dispersion to form a chirped pulse. The stretched chirped pulse is coupled into the three-dimensional photonic crystal 7 by the coupling element 6, and the other pump light The light emitted by the pump light laser is generated by the second pulse generator 15. The pulsed pump light enters the polarizer 14 and then becomes linearly polarized light, which is then stretched by the second stretcher 13. The pulse width of the pump light pulse stretched is greater than The pulse width of the signal pulse light, in the three-dimensional photonic crystal 7, the pump light is adjusted into the required spot shape by the shaper 12, and enters the three-dimensional photonic crystal 7 from the side of the three-dimensional photonic crystal 7, and the pump light pulse must completely contain When the signal light Is and the pump light Ip meet in the three-dimensional photonic crystal 7, the signal light Is is amplified due to the nonlinear coupling effect, and the three-dimensional photonic crystal 7 amplifies and outputs two kinds of light. The amplified signal light Gs, the other light is called idle light Gi, and the wavelengths of the two kinds of light are separated after passing through the isolator 8 and the light splitting element 9. The isolator 8 prevents the advancing light from being reflected back when it encounters the surface of the optical element The light breaks the three-dimensional photonic crystal 7, the dispersion of the amplified signal light is compensated by the compressor 10, and the pulse signal light is compressed into an ultrashort chirped pulse, and the amplified and compressed signal light is sent to the receiving device 11.

The coupling amplification of signal light and pump light uses a nonlinear phenomenon in three-dimensional photonic crystals, which transfers a small part of the incident light power to Stokes waves with a lower frequency than it; its working principle is based on three-dimensional photonic Stimulated Raman scattering (SRS) effect of crystals. The SRS in 3D photonic crystals originates from the third-order nonlinear effect of 3D photonic crystals, manifested as the interaction between pump photons, Stokes photons and optical branch phonons: pump photons are absorbed by medium molecules , the electrons transition from the ground state to the virtual energy level, the size of the virtual energy level is determined by the energy of the pump light, and then the electrons in the virtual energy level return to the high energy level of the vibration state under the induction of the signal light, generating a Photons with the same frequency, same phase, and same direction are called Stokes photons. If a signal light and a strong pump light wave are in the three-dimensional photonic crystal at the same time, and the wavelength of the signal light is within the Raman gain spectrum bandwidth of the pump light wave, the signal light can be amplified by the three-dimensional photonic crystal.

In the device shown in Fig. 1, the signal light source 1 uses a solid-state laser as the light source, the output wavelength is 10645 nm, and the output energy is 2.7 μJ. The three-dimensional photonic crystal point 702 is in the shape of a sphere, the substrate of the three-dimensional photonic crystal is quartz, doped with erbium, and the frequency of the signal light is tripled to 354nm. Experiments show that the signal light with a wavelength of 354nm is amplified more than 600 times, and the pulse width is 2.1×10 ^-15 seconds.

Experiments show that the device of the invention has the characteristics of simple structure, easy operation and high pumping efficiency.

Claims (10)

1. An ultrashort chirped pulse photonic crystal optical parameter amplification device, characterized in that the core element of the device is a three-dimensional photonic crystal (7), and the optical elements entering the signal light path of the three-dimensional photonic crystal (7) are successively signal Light source (1), first pulse generator (2), optical collimation element (3), polarizing element (4), first stretcher (5) and coupling element (6); isolator (8) and light splitter After the element (9) is positioned at the described three-dimensional photonic crystal (7), the optical element entering the pump light path of the three-dimensional photonic crystal (7) from the side is the pump light laser (16) along the advancing direction of the pump light. ), a second pulse generator (15), a polarizer (14), a second stretcher (13) and a shaper (12); the isolator (8) is followed by the splitter element (9) and compression device (10), the signal light receiving device (11) is behind the compressor (10), and the pulse width of the pumping light pulse broadening entering the three-dimensional photonic crystal (7) is greater than the pulse width of the signal light pulse broadening, and the pumping The light pulses fully envelope the signal light pulses. 2. The ultrashort chirped pulse photonic crystal optical parametric amplification device according to claim 1, characterized in that the signal light source (1) is a laser, and the laser and the pumping laser (16) are fiber solid-state lasers, or semiconductor lasers. 3. The ultrashort chirped pulse photonic crystal optical parametric amplification device according to claim 1, characterized in that the first pulse generator (2) and the second pulse generator (15) are electro-optical modulated pulse generators device. 4. The ultrashort chirped pulse photonic crystal optical parametric amplification device according to claim 1, characterized in that said polarizing element (4) and polarizer (14) are Nickel prisms, or polarizers, or Wollaston Prism. 5. The ultrashort chirped pulse photonic crystal optical parametric amplification device according to claim 1, characterized in that the light collimation element (3) is composed of a semi-convex spherical lens. 6. The ultrashort chirped pulse photonic crystal optical parametric amplification device according to claim 1, characterized in that the first stretcher (5) and the second stretcher (13) have the same structure, mainly comprising a blazed grating (501), convex reflector (502) and concave reflector (503), its optical path is that the input light is reflected by the blazed grating (501), reflected by the concave reflector (503), reflected by the convex reflector (502), and then through the concave surface Reflected by the mirror (503) to output. 7. The ultrashort chirped pulse photonic crystal optical parameter amplification device according to claim 1, characterized in that the three-dimensional photonic crystal (7) is arranged on a three-dimensional photonic crystal substrate (701) with several three-dimensional photonic crystal points (702) constituted. 8. The ultra-short chirped pulse photonic crystal optical parameter amplification device according to claim 7, characterized in that the three-dimensional photonic crystal point (702) is composed of doped glass or quartz doped material, three-dimensional The refractive index of the photonic crystal point (702) is greater than that of the three-dimensional photonic crystal substrate (701), and the doped elements are rare elements of ytterbium and erbium. The three-dimensional photonic crystal point (702) is spherical, cubic, cuboid, Rhombus shape, polyhedron shape or curve shape; arrangement of three-dimensional photonic crystal points (702) is rhombus shape, square shape, rectangle shape or polygon shape. 9. The ultrashort chirped pulse photonic crystal optical parametric amplification device according to claim 1, characterized in that the light splitting element (9) is a planar transmission grating, or a transmission blazed grating, or a transmission concave grating. 10. The ultrashort chirped pulse photonic crystal optical parameter amplification device according to claim 1, characterized in that the receiving device (11) is a CCD diode array detector, a photodiode, a photomultiplier tube, a multi-channel board , oscilloscope, or computer.

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