CN110854659B - Double-frequency Faraday semiconductor laser and implementation method thereof - Google Patents
Double-frequency Faraday semiconductor laser and implementation method thereof Download PDFInfo
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Abstract
The invention provides a double-frequency Faraday semiconductor laser, which comprises a laser diode (1), a collimating lens (2), a Faraday atomic filter and a laser cavity mirror (7), wherein the Faraday atomic filter comprises a first polarization beam splitter prism (3), an alkali metal atom gas chamber (4) and a second polarization beam splitter prism (5); two laser modes are selected after output light of the laser diode (1) enters the alkali metal atom gas chamber (4), the angle between the laser cavity mirror (7) and the incident light is adjusted, reflected light of the laser cavity mirror (7) returns to the semiconductor laser diode (1), oscillation and amplification are carried out in the resonant cavity until the reflected light exceeds the oscillation threshold value of the laser, and double-frequency laser is output at the first polarization beam splitter prism or the second polarization beam splitter prism. The tunability of the output frequency of the dual-frequency semiconductor laser can be realized by changing the temperature and the magnetic field condition of the atomic gas chamber, and the transmission spectrum comprises two stable transmission peaks with similar transmissivity and can stably work for a long time.
Description
Technical Field
The invention belongs to the technical field of semiconductor lasers, and particularly relates to a semiconductor laser for realizing dual wavelengths by utilizing frequency selection of a Faraday atomic optical filter.
Background
A dual wavelength laser is a laser that is capable of generating two laser wavelengths in one device. Dual wavelength lasers with large wavelength separations can provide dual uses in a single device, thereby achieving cost-effectiveness, efficiency, and versatility improvements.
Dual wavelength lasers have found wide application in many fields, such as ultrafast optical communication, wavelength division multiplexing, and terahertz radiation generation. Conventional dual wavelength lasers are mainly based on fiber lasers and solid state lasers. While fiber lasers have attractive properties such as narrow linewidth and low noise, they typically require the use of a filtering element such as a distributed bragg mirror to select the lasing mode. Thus, most of these lasers are constructed with relatively long cavities, which can make it difficult to obtain a single longitudinal mode at each desired wavelength, and are random. On the other hand, a dual-wavelength solid-state laser generally requires pump light to act on a laser medium, such as neodymium-doped yttrium aluminum garnet (Nd: YAG), neodymium-doped yttrium lithium fluoride (Nd: YLF), neodymium-doped yttrium vanadate (Nd: YVO), neodymium-doped yttrium aluminum garnet (Nd: YAP), erbium-doped yttrium aluminum garnet (Er: YAG), etc., to realize dual-wavelength output based on two emission peaks of an emission spectrum of the laser medium; or a laser based on the broadband emission spectrum of the laser medium, such as a titanium sapphire laser, and then the dual-wavelength operation is realized through a frequency-selective device. In addition, a method for expanding the frequency range of the existing laser source is also provided by nonlinear optical devices such as a harmonic generator and a parametric oscillator; in addition to this, there is a two-wavelength semiconductor laser based on an external cavity which selects a wavelength using a nonlinear crystal element.
In recent years, a semiconductor laser based on mode selection of a Faraday atomic filter is proposed, and according to reports, the single frequency output by the semiconductor laser is insensitive to the current and temperature change of a laser diode and has good stability. There is also a report on a method of filtering light by using a cascade atomic filter having only one frequency transmission peak, and the laser output frequency is always a single stable frequency, and a laser capable of realizing stable dual-frequency output has not been found yet.
With the increasingly wide application of dual-wavelength lasers in many important fields such as optical communication, photodynamic medical treatment, optical calculation, nonlinear frequency conversion, environmental monitoring, laser remote sensing, laser radar and spectroscopy research, dual-wavelength lasers have become an important research direction. At present, many applications are searching for new laser devices, and the concept of multi-wavelength laser has existed from the early stage of laser, but the status of the multi-wavelength laser in the laser field is still rather blurred. The opportunity to explore these multi-wavelength laser devices may pave the way to find new application areas for multi-wavelength, multi-multiplexer devices.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a semiconductor laser which is simple in structure and has stable double-frequency output.
The idea of the invention is to adopt a Faraday atom filtering technology, and based on the condition that a Faraday atom filter has two transmission peaks with similar transmissivity under specific temperature and magnetic field conditions, two laser modes are selected in a semiconductor laser cavity, and double-frequency output of the laser is finally realized, so that a beat frequency signal under microwave frequency is generated and further used as a microwave signal source in a signal processing system.
Based on the above thought, the invention provides a dual-frequency faraday semiconductor laser, which comprises a laser diode 1, a collimating lens 2, a faraday atomic filter, a laser cavity mirror 7 and a piezoelectric ceramic 8 which are sequentially arranged on a light path, wherein an antireflection film is plated on an output light end face of the laser diode 1; the Faraday atomic filter comprises a first polarization beam splitter prism 3, an alkali metal atom gas chamber 4 and a second polarization beam splitter prism 5 which are sequentially arranged, an axial static magnetic field is applied to the alkali metal atom gas chamber 4 through a permanent magnet 5, and the position relation between the first polarization beam splitter prism 3 and the second polarization beam splitter prism 5 is orthogonal;
coherent light beams emitted by the laser diode 1 are collimated into parallel light through the collimating lens 2, the parallel light passes through the first polarization beam splitter prism 1 to obtain horizontal polarized light or vertical polarized light with the same emergent direction as the laser diode 1, the parallel light is subjected to mode selection after entering the alkali metal atom gas chamber 4 and reaches the laser cavity mirror 7 through the second polarization beam splitter prism 5; the reflected light of the laser cavity mirror 7 and the incident light are in a collinear reverse direction by adjusting the angle between the laser cavity mirror 7 and the incident light, the reflected light returns to the semiconductor laser diode 1 after passing through the second polarization beam splitter prism 5, the atom air chamber 4, the first polarization beam splitter prism 3 and the collimating lens 2, and is oscillated and amplified in a resonant cavity formed by the laser cavity mirror 7 and the output light end face of the semiconductor laser diode 1 until the oscillation threshold of the laser is exceeded, so that the dual-wavelength laser is output at the first polarization beam splitter prism or the second polarization beam splitter prism.
In the invention, the alkali metal atom air chamber is filled with rubidium atoms or cesium atoms.
According to a preferred embodiment, a piezoelectric ceramic 8 is arranged on the laser cavity mirror 7, and the cavity length of the resonant cavity is adjusted through the piezoelectric ceramic 8.
The transmission spectrum of the double-frequency Faraday semiconductor laser comprises two transmission peaks with similar transmissivity, and the distance between the two transmission peaks is 5GHz-10 GHz.
According to another preferred embodiment, the gain medium may be selected from a variety of options, for example, a solid gain medium with an antireflection coating on its end face is used as the gain medium instead of the semiconductor laser diode.
According to another preferred embodiment, the vacuum atomic gas cell can be replaced by a buffer gas atomic gas cell, thereby increasing the transmission spectrum bandwidth.
In a particularly preferred embodiment, the alkali metal atomic gas cell 4 is filled with cesium atoms at an atomic gas cell temperature of 36-53 deg.C, and a magnetic field of 300-350 gauss is applied to the atomic gas cell by the permanent magnet 5.
As another particularly preferred embodiment, 5 Torr argon gas is filled in the alkali metal atomic gas chamber 4 as a buffer gas, the temperature of the atomic gas chamber is 43 to 55 ℃, and a magnetic field of 500-700 gauss is applied to the atomic gas chamber by the permanent magnet 5.
Alternatively, the other surface of the laser diode 1 may be coated with a high-reflective film.
In the present invention, the antireflection film and the high reflection film are all conventional techniques in the art, and those skilled in the art can plate the antireflection film and the high reflection film on the laser diode according to the teaching of the prior art.
Emergent light in the horizontal or vertical direction can be obtained by changing the placement position of the semiconductor laser diode, and under the condition that the first polarization beam splitter prism 3 and the second polarization beam splitter prism 5 are in an orthogonal position relationship, the semiconductor laser has two realization modes:
first, a laser diode 1 emits a horizontally polarized coherent light beam, the horizontally polarized coherent light beam is collimated into parallel light by a collimating lens, the parallel light beam enters a first polarization beam splitter prism to obtain horizontally polarized light, the horizontally polarized light passes through an atomic gas cell 4 for mode selection, the polarization direction of the mode-selected incident light is converted into vertically polarized light, and the polarization direction of the mode-unselected incident light is still horizontally polarized light. Therefore, the obtained vertically polarized light subjected to mode selection enters the second polarization splitting prism and reaches the laser cavity mirror 7, and the horizontally polarized light not subjected to mode selection is reflected and output by the second polarization splitting prism 5. The angle of the incident light of the laser cavity mirror 7 and the selected mode is adjusted, so that the reflected light of the laser cavity mirror 7 and the incident light of the selected mode are collinear and reverse, the reflected light returns to the semiconductor laser diode along the original light path, and is oscillated and amplified in a resonant cavity formed by the output light end surface of the semiconductor laser diode and the laser cavity mirror to exceed the oscillation threshold of the laser, so that the light reflected and output by the second polarization splitting prism is directly output as the output laser.
The other difference is that the laser diode 1 is placed at a different position to emit a vertically coherent light beam, and the vertically coherent light beam is collimated into vertically parallel light and then enters the first polarization beam splitter prism to obtain vertically polarized light. Because the vertical polarization coherent light beam emitted by the anti-reflection film coated laser diode 1 contains a small part of horizontal polarization light, the horizontal polarization light is reflected and output when passing through the first polarization beam splitter prism 3. The vertical light which penetrates through the first polarization beam splitter prism is used as incident light, the mode is selected through the atomic gas chamber 4, the polarization direction of the incident light of the mode is converted into horizontal polarized light, therefore, the light of the mode is selected to reach the laser cavity mirror 7 through the second polarization beam splitter prism 5, the reflected light of the laser cavity mirror 7 and the incident light of the selected mode are enabled to be collinear and reverse by adjusting the angle of the incident light of the laser cavity mirror 7 and the selected mode, then the reflected light is all returned to the semiconductor laser diode 1 along the original light path, the reflected light is oscillated and amplified in a resonant cavity formed by the output light end face of the semiconductor laser diode 1 and the laser cavity mirror 7 to exceed the oscillation threshold value of a laser, and the light which is reflected and output by the first polarization beam splitter prism is directly output as output laser.
Experiments prove that the transmission spectrum of the Faraday atomic optical filter can obtain two stable transmission peaks with similar transmissivity by adjusting the conditions of temperature and magnetic field, so that two laser modes are selected, and the stable output of the dual-wavelength laser is realized.
Furthermore, the invention also proves that the frequencies corresponding to the two transmission peaks of the Faraday atomic filter can be changed by changing the temperature and the magnetic field condition of the atomic gas chamber in the Faraday atomic filter, so that the two selected laser modes are changed, and the tunability of the output frequency of the double-frequency semiconductor laser is realized. The invention adopts a method that a laser diode plated with an antireflection film is matched with a Faraday atom filter and a laser cavity mirror for feedback, and realizes a dual-frequency Faraday semiconductor laser. When the Faraday atomic filter works under the specific temperature and magnetic field conditions, the transmission spectrum of the Faraday atomic filter comprises two stable transmission peaks with similar transmissivity, so that the frequencies of the double-frequency Faraday semiconductor laser fed back and output by the laser cavity mirror are ensured to respectively correspond to the double transmission peaks of the Faraday atomic filter, and the Faraday atomic filter can work stably for a long time.
In the invention, the anti-reflection film plated laser diode has good immunity to the fluctuation noise of external environment factors, working temperature of the diode, working current of the diode and other factors because of no competition of an inner cavity mode, and the dual-frequency laser can continuously work on the frequency corresponding to the dual transmission peaks of the transmission spectrum of the Faraday atomic filter for a long time. The invention creatively adopts the Faraday atomic filter to realize the output of the dual-frequency laser, and when the temperature and the magnetic field condition of an atomic gas chamber in the Faraday atomic filter are changed, the frequencies corresponding to two transmission peaks of the Faraday atomic filter can be changed, so that two selected laser modes are changed, and the tunability of the output wavelength of the dual-frequency semiconductor laser is realized.
Drawings
Fig. 1 is a 852nm double-frequency faraday semiconductor laser of cesium atom of example 1;
FIG. 2 is a 852nm double-frequency Faraday semiconductor laser of cesium atom of example 2;
FIG. 3 is the transmission spectrum of a 852nm Faraday anomalous dispersion atomic filter with cesium atoms for example 1;
FIG. 4 shows beat signals of a 852nm cesium atom dual-frequency Faraday semiconductor laser and a 852nm single-frequency interference filter external-cavity semiconductor laser in example 1;
fig. 5 is a relationship between the center frequency of the beat signal of two laser modes output by the 852nm double-frequency faraday semiconductor laser with cesium atoms and the temperature of the gas chamber with cesium atoms in example 1;
fig. 6 is a graph showing the relationship between the line width of the beat signal of the cesium atom 852nm dual-frequency faraday semiconductor laser of example 1 outputting a dual-wavelength laser and the temperature of the faraday anomalous dispersion atomic filter;
fig. 7 is the transmission spectrum of a 852nm faraday atom filter of cesium atoms of example 3.
Wherein: 1. the laser diode comprises a laser diode body coated with an antireflection film, 2 parts of a collimating lens, 3 parts of a first polarization beam splitter prism, 4 parts of a cesium atom air chamber, 5 parts of a permanent magnet, 6 parts of a second polarization beam splitter prism, 7 parts of a laser cavity mirror, 8 parts of a piezoelectric ceramic.
Detailed Description
The following examples serve to illustrate the technical solution of the present invention without limiting it.
Example 1
As shown in fig. 1, the 852nm double-frequency faraday semiconductor laser comprises a laser diode 1, a collimating lens 2, a first polarization splitting prism 3, a cylindrical cesium atom gas chamber 4 with a length of 3 cm and a diameter of 1.5 cm, a second polarization splitting prism 6, a laser cavity mirror 7 and a piezoelectric ceramic 8 arranged on the laser cavity mirror 7, which are sequentially arranged on a light path, wherein a permanent magnet 5 is arranged outside the cesium atom gas chamber, and the cesium atom gas chamber 4, the permanent magnet 5 and the polarization splitting prisms positioned at two sides form a cesium atom faraday atom filter. An antireflection film is plated on the end face of the output light of the laser diode 1, a high-reflection film is plated on the other face of the output light, and the first polarization beam splitter prism and the second polarization beam splitter prism are arranged in an orthogonal relation.
When the laser diode works, a laser diode 1 coated with an antireflection film emits a horizontally polarized coherent light beam, the horizontally polarized coherent light beam is collimated into parallel light through a collimating lens 2, the parallel light is used as incident light of a cesium atom Faraday atom optical filter, the incident light is still horizontally polarized after passing through a first polarization splitting prism 3, and then the mode selection is carried out by a cesium atom air chamber 4. The polarization direction of the incident light of the selected mode is converted into vertical polarized light, the polarization direction of the incident light of the unselected mode is unchanged and is still horizontal polarized light, therefore, the vertical polarized light of the selected mode passes through the second polarization beam splitter prism 6 to reach the laser cavity mirror 7, and the horizontal polarized light of the unselected mode is reflected and output by the second polarization beam splitter prism 6.
And adjusting the angle of the incident light of the vertical normal light of the laser cavity mirror 7 and the selected mode to ensure that the reflected light of the laser cavity mirror 7 and the incident light of the selected mode are collinear and reverse, all the light reflected by the laser cavity mirror 7 returns to the anti-reflection film-coated semiconductor laser diode 1 along the original path, and the light is oscillated and amplified in a resonant cavity formed by the output light end surface of the semiconductor laser diode 1 and the laser cavity mirror 7 to exceed the oscillation threshold of the laser, so that the light reflected and output by the second polarization beam splitter prism 6 is directly output as the output laser.
Thus, under the conditions of the temperature of 36-53 ℃ and the magnetic field of 300-350 Gauss, the transmission spectrum of the cesium atom Faraday anomalous dispersion atomic filter of the embodiment is verified to comprise two stable transmission peaks with similar transmission rates, so that two laser modes are selected, and stable output of a cesium atom 852nm dual-wavelength laser is realized. In the temperature and magnetic field condition range, the temperature and magnetic field condition of a cesium atom gas chamber in the cesium atom Faraday anomalous dispersion atomic optical filter are adjusted, and the frequencies corresponding to the two transmission peaks can be changed, so that the two selected laser modes are changed, and the tunability of the output wavelength of the cesium atom 852nm dual-wavelength semiconductor laser is realized.
Fig. 3 shows the transmission spectrum of the 852nm faraday anomalous dispersion atomic filter of cesium atoms under different atomic cell temperature and magnetic field strength conditions, the abscissa is frequency and the ordinate is transmittance, wherein the left graph corresponds to the transmission spectrum of 852nm ground state F =3 transition of cesium atoms, the right graph corresponds to the transmission spectrum of 852nm ground state F =4 transition of cesium atoms, and the frequency interval between the ground state F =3 and the ground state F =4 is 9.19GHz as can be seen from the first set of graphs, namely the transmission spectrum of the 852nm faraday anomalous dispersion atomic filter of cesium atoms comprises two transmission peaks at the ground state F =3 transition and the ground state F =4 transition. The second set of graphs corresponds to a transmission spectrum of a 852nm cesium atom faraday atom filter including two transmission peaks at a ground state F =3 transition and a ground state F =4 transition at a temperature of 43 ℃ and a magnetic field of 330 gauss. The third group of graphs corresponds to the transmission peak at 53 ℃ in the case of a magnetic field of 330 gauss, and although many small peaks are included, two highest peaks are clearly present for F =4 and F =3, respectively, and dual-frequency laser light can be output.
Fig. 4 shows beat signals of a 852nm cesium double-frequency faraday semiconductor laser and a 852nm single-frequency interference filter external cavity semiconductor laser realized by the prior art. The abscissa is frequency, and the ordinate is signal intensity, since the 852nm double-frequency faraday semiconductor laser of the cesium atom in this embodiment outputs two laser wavelengths, which respectively correspond to ground state F =3 and F =4 transitions, the wavelength of the external cavity semiconductor laser of the single-frequency 852nm interference filter is adjusted to correspond to ground state F =4, as shown in the figure, four beat frequency signals appear, which sequentially from left to right: a single-frequency 852nm interference filter external cavity semiconductor laser and a cesium atom 852nm double-frequency Faraday semiconductor laser F =4 laser mode beat frequency signal; beat signals of the first signal and the third signal; a beat frequency signal of a 852nm cesium double-frequency Faraday semiconductor laser F =3 laser mode and F =4 laser mode; a single-frequency 852nm interference filter external cavity semiconductor laser and a cesium atom 852nm double-frequency Faraday semiconductor laser F =3 beat frequency signal of a laser mode.
As can be seen from this, the 852nm dual-band faraday semiconductor laser of the present embodiment realizes a dual-wavelength output, and the transmission spectrum of the 852nm faraday anomalous dispersion atomic filter corresponding to cesium atoms includes two transmission peaks at the ground state F =3 transition and the ground state F =4 transition, respectively.
The change relationship between the center frequency of the beat frequency signal of two laser modes output by the 852nm double-frequency Faraday semiconductor laser and the temperature of the cesium atom gas chamber is examined, as shown in fig. 5. The abscissa is the temperature of the cesium atom gas chamber and the ordinate is the frequency.
As can be seen from fig. 5, by adjusting the temperature of the cesium atom gas chamber, the interval between the two modes of the dual-wavelength laser changes with the temperature, so that the output wavelength tunability of the 852nm dual-frequency faraday semiconductor laser with cesium atoms is realized.
Further examining the relationship between the beat frequency signal line width of the cesium atom 852nm dual-frequency faraday semiconductor laser outputting the dual-wavelength laser and the temperature change of the cesium atom gas chamber, as shown in fig. 6. The abscissa is the temperature of the cesium atom gas chamber and the ordinate is the line width.
As can be seen from FIG. 6, by adjusting the temperature of the cesium atom gas chamber, the line width of the dual-wavelength laser in the two modes can be changed to a certain extent, but is basically about 1kHz, which proves the narrow line width characteristic of the laser output by the cesium atom 852nm dual-frequency Faraday semiconductor laser under the conditions of the temperature of 36-53 ℃ and the magnetic field of 300-350 Gauss.
Example 2
A 852nm cesium atom dual-frequency faraday semiconductor laser as shown in fig. 2 is used to explain another positional relationship between the first and second polarization beam splitters.
Unlike embodiment 1, the arrangement direction of the laser diode was changed so that the output light was a vertically polarized coherent light beam, and the arrangement direction of the first polarization beam splitter prism was changed depending on the laser diode (while the placement angle of the second polarization beam splitter prism was changed in order to keep the second polarization beam splitter prism orthogonal thereto).
Therefore, the vertically polarized coherent light beam emitted by the anti-reflection film coated laser diode 1 becomes vertically polarized light after being collimated by the collimating lens, so that the vertically polarized light is still vertically polarized after being incident to the first polarization beam splitter prism, and the vertically polarized coherent light beam emitted by the anti-reflection film coated laser diode 1 contains part of horizontally polarized light which is reflected and output when passing through the first polarization beam splitter prism 3. Vertical light emitted by the first polarization beam splitter prism is used as incident light, the mode of the vertical light passes through the atomic gas chamber 4, the polarization direction of the incident light of the mode selection is converted into horizontal polarized light, therefore, the light of the mode selection passes through the second polarization beam splitter prism 5 to reach the laser cavity mirror 7, the angle between the laser cavity mirror 7 and the incident light of the mode selection is adjusted, the reflected light of the laser cavity mirror 7 and the incident light of the mode selection are in collinear reversal direction, then the reflected light is totally returned to the semiconductor laser diode 1 along the original light path, oscillation and amplification are carried out in a resonant cavity formed by the output light end face of the semiconductor laser diode 1 and the laser cavity mirror 7 until the oscillation threshold value of the laser is exceeded, and the light reflected and output by the first polarization beam splitter prism is directly output as output laser.
Example 3
The dual-frequency Faraday semiconductor laser with the same structure and position relationship as example 1 was confirmed to obtain stable dual-frequency laser output, except that 5 Torr argon gas was filled in the cesium atomic gas chamber as a buffer gas, and the transmission spectrum was verified under the conditions of a magnetic field of 500-700 Gauss and a temperature of 43-55 ℃ as shown in FIG. 7.
The above embodiments show that the frequency control unit used in the 852nm cesium atom dual-frequency faraday semiconductor laser is a 852nm cesium atom faraday anomalous dispersion atomic optical filter including two transmission peaks at the ground state F =3 transition and the ground state F =4 transition, and the present invention uses the innovative structure and principle for the first time to realize the dual-wavelength semiconductor laser, and the wavelength of the dual-wavelength semiconductor laser is different from that of the existing dual-wavelength laser based on essence.
It should be noted that the present invention is not limited to the use of laser diodes as gain media, but also includes other solid gain media with an antireflection coating on the facet. The invention is also not limited to cesium atoms, but is equally applicable to all possible spectral lines corresponding to various filters of alkali metal atoms having a double transmission peak.
Claims (4)
1. The dual-frequency Faraday semiconductor laser comprises a laser diode (1), a collimating lens (2), a Faraday atomic filter and a laser cavity mirror (7) which are sequentially arranged on a light path, and is characterized in that an anti-reflection film is plated on an output light end face of the laser diode (1); the Faraday atomic filter comprises a first polarization beam splitter prism (3), an alkali metal atom air chamber (4) and a second polarization beam splitter prism (5), wherein the first polarization beam splitter prism, the alkali metal atom air chamber (4) and the second polarization beam splitter prism (5) are sequentially arranged, cesium atoms are filled in the alkali metal atom air chamber (4), an axial static magnetic field is applied to the alkali metal atom air chamber (4) through a permanent magnet (5), and the position relation of the first polarization beam splitter prism (3) and the second polarization beam splitter prism (5) is orthogonal;
wherein, cesium atoms are filled in the alkali metal atom air chamber (4), the temperature of the atom air chamber is 36-53 ℃, and a 300-350 Gauss magnetic field is applied to the atom air chamber through the permanent magnet (5); or
5 torr of argon gas is filled in the alkali metal atomic gas chamber (4) to be used as buffer gas, the temperature of the atomic gas chamber is 43-55 ℃, and a 500-700 Gauss magnetic field is applied to the atomic gas chamber through the permanent magnet (5);
coherent light beams emitted by the laser diode (1) are collimated into parallel light through the collimating lens (2), the parallel light passes through the first polarization splitting prism (1) to obtain horizontal polarized light or vertical polarized light with the same emergent direction as the laser diode (1), and the parallel light is incident into the alkali metal atom gas chamber (4), then is selected into two laser modes and reaches the laser cavity mirror (7) through the second polarization splitting prism (5); the angle between the laser cavity mirror (7) and incident light is adjusted, so that the reflected light of the laser cavity mirror (7) and the incident light are in collinear reversal, the reflected light returns to the semiconductor laser diode (1) after passing through the second polarization splitting prism (5), the atom air chamber (4), the first polarization splitting prism (3) and the collimating lens (2), and is oscillated and amplified in a resonant cavity formed by the laser cavity mirror (7) and the output light end face of the semiconductor laser diode (1) until the oscillating threshold exceeds the oscillation threshold of a laser, so that the first polarization splitting prism or the second polarization splitting prism outputs double-frequency laser.
2. A dual-frequency faraday semiconductor laser according to claim 1, characterized in that a piezoelectric ceramic (8) is arranged on the laser cavity mirror (7), by means of which piezoelectric ceramic (8) the cavity length of the resonant cavity is adjusted.
3. The dual-frequency faraday semiconductor laser of claim 1, wherein the transmission spectrum of the dual-frequency faraday semiconductor laser comprises two transmission peaks of similar transmission, and the two transmission peaks are spaced apart by 5GHz-10 GHz.
4. A dual-frequency faraday semiconductor laser according to claim 1, characterized in that the other side of the laser diode (1) is coated with a high-reflectivity film.
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| GB2598086A (en) * | 2020-08-03 | 2022-02-23 | Univ Birmingham | Frequency control of orthogonal polarisation modes in an optical cavity |
| CN112018590B (en) * | 2020-09-07 | 2021-11-02 | 北京大学 | Multi-wavelength non-atomic resonance Faraday semiconductor laser |
| CN113097854B (en) * | 2021-04-02 | 2022-09-30 | 温州激光与光电子协同创新中心 | Faraday active optical clock-based dark cavity laser and implementation method thereof |
| CN113555766A (en) * | 2021-05-14 | 2021-10-26 | 温州激光与光电子协同创新中心 | Faraday laser based on pyramid array external cavity reflector and implementation method thereof |
| CN114498296B (en) * | 2022-01-13 | 2024-02-02 | 浙江法拉第激光科技有限公司 | 852nm wavelength high-power Faraday laser and implementation method thereof |
| CN115021050B (en) * | 2022-05-06 | 2024-08-16 | 北京大学 | THz radiation source and THz interval dual-wavelength Faraday laser |
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