[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.
[0033] figure 1 It is a schematic flowchart of an embodiment of an external cavity feedback laser generation method immune to temperature and current noise in the present invention. like figure 1 shown, including the following steps:
[0034] Step 101, using the narrow linewidth transmission spectrum of the Faraday anomalous dispersion atomic optical filter, the temperature and magnetic field tuning characteristics of the transmission spectrum, and the long-term stability of the transmission spectrum of the Faraday anomalous dispersion atomic optical filter as an anti-reflection coating Frequency-selective devices for diode lasers;
[0035] Step 102, the laser diode coated with an anti-reflection coating, the light beam after passing through the collimating lens, passes through the narrow line width mode selection of the Faraday anomalous dispersion atomic filter, and feeds back the laser coated with the anti-reflection coating by the external cavity mirror diode. That is, the narrow transmission spectrum of the Faraday anomalous dispersion atomic filter is used as the mode selection device, and the cavity mirror of the laser epitaxy cavity is used to form the external cavity feedback.
[0036] Step 103 , under the combined effect of the frequency selection of the Faraday anomalous dispersion atomic filter and the feedback of the external cavity mirror, the laser diode coated with the anti-reflection coating outputs laser light corresponding to the transmission spectrum of the atomic filter.
[0037] The embodiment of the present invention provides an external cavity feedback laser method immune to temperature and current noise, and the existing grating external cavity feedback laser method, the existing interference filter external cavity feedback laser method, and the existing non-plated laser method Compared with the external cavity feedback laser method of the atomic optical filter of the anti-reflection film, the present invention guarantees The frequency of the output laser can work stably on the transmission spectrum of the Faraday anomalous dispersion atomic filter of a specific atom for a long time, and the output laser wavelength or frequency can be immune to the temperature and current noise of the semiconductor.
[0038] Further, in the above figure 1 On the basis of the illustrated embodiment, the length of the laser cavity can be adjusted by adjusting the control of the piezoelectric ceramics on the laser epitaxial cavity mirror with piezoelectric ceramics, so that the output laser can be stabilized on a specific atomic spectral line.
[0039] Further, in the above figure 1On the basis of the illustrated embodiment, other laser gain media are used to replace the semiconductor laser gain media to form a cavity-less external-cavity feedback laser using a Faraday anomalous dispersion atomic filter. Note that the medium described here is the laser gain medium coated with an anti-reflection film on the surface according to the special requirements of the present invention. Said other laser gain media include solid laser gain media, gas laser gain media, liquid laser gain media and fiber laser gain media, as long as the gain spectrum of these laser gain media has a corresponding transmission spectrum to the Faraday anomalous dispersion atomic filter frequency, the method of the present invention can also be used to implement the external cavity feedback laser using the Faraday anomalous dispersion atomic filter. The difference from the existing technology is that the special feature of the present invention is that the surface of the laser gain medium must be coated with an anti-reflection film corresponding to the laser wavelength. Compared with the prior art, the invention completely eliminates the internal cavity mode, and only determines the position of the external cavity mode by the atomic optical filter.
[0040] In the embodiment of the present invention, when the Faraday anomalous dispersion atomic filter of the alkali metal atom is utilized, the gain spectrum of the gain medium of the semiconductor laser coated with an anti-reflection film needs to be the same as the Faraday anomalous dispersion of the corresponding alkali metal atom. The transmission spectrum of the atomic filter corresponds. For example, in the atomic state representation of alkali metals, the principal quantum number n=2 (lithium), 3 (sodium), 4 (potassium), 5 (rubidium) or 6 (cesium), and one of the spectral lines D can be used 1 (ground state ns 2 S 1/2 to excited state np 2 P 1/2 Transition between) spectral line, also can use a D 2 (ground state ns 2 S 1/2 to excited state np 2 P 3/2 transition between) spectral lines. Similarly, one of the spectral lines corresponding to the highly excited state can be used, such as the ground state ns 2 S 1/2 to the excited state (n+1)p 2 P 1/2 Between the transition lines, other lines can also be used, such as the ground state ns 2 S 1/2 to the excited state (n+1)p 2 P 3/2 transition between. To give a more specific example: for the Faraday anomalous dispersion atomic optical filter of cesium atoms, the gain spectrum of the gain medium of the semiconductor laser coated with an anti-reflection coating needs to be the same as the transmission spectrum of the Faraday anomalous dispersion atomic optical filters of cesium atoms Corresponding, such as 852.11nm (ground state 6s 2 S 1/2 to excited state 6p 2 P 3/2 Transition line between), 894.35nm (ground state 6s 2 S 1/2 to excited state 6p 2 P 1/2 Between transition lines), 455.54nm (ground state 6s 2 S 1/2 to excited state 7p 2 P 3/2 Between transition lines), 459.32nm (ground state 6s 2 S 1/2 to excited state 7p 2 P 1/2 transition line between), 388.87nm (ground state 6s 2 S 1/2 to excited state 8p 2 P 1/2 Between transition lines), 387.54nm (ground state 6s 2 S 1/2 to excited state 8p 2 P 3/2 Between transition lines), 1358.9nm (excited state 6p 2 P 1/2 to excited state 7s 2 S 1/2 transition line between), 1469.5nm (excited state 6p 2 P 3/2 to excited state 7s 2 S 1/2 between transition lines). The similar situation about the spectral lines of other gain atoms or gain medium materials will not be described in detail one by one.
[0041] figure 2 It is a structural schematic diagram of the first embodiment of an external cavity feedback laser immune to temperature and current noise in the present invention. like figure 2 As shown, the laser includes: a laser semiconductor diode 1 coated with an anti-reflection film, a collimating lens 2, an atomic filter 3, an external cavity mirror 4 with a piezoelectric ceramic 5, and a related control circuit 6. The functions of the above components are described as follows: the laser semiconductor diode 2 coated with an anti-reflection film emits spontaneous emission fluorescence with a spectral width of the order of nm under the current drive of the control circuit 6 and is collimated by the collimating mirror 2. The spectrum of these fluorescence falls within The light energy within the pass band of the atomic filter 3 passes through the atomic filter, and is fed back to the laser semiconductor diode coated with an anti-reflection coating under the reflection of the external cavity mirror 4 to form a stimulated emission 7 laser output. The control circuit 6 is used to control the temperature and current of the laser semiconductor diode 1 coated with an anti-reflection film, the temperature and magnetic field of the atomic filter 3, the voltage of the piezoelectric ceramic 5, and the frequency stabilization of the laser frequency. The piezoelectric ceramic 5 is used to adjust the cavity length of the external cavity to precisely control the frequency of the output laser 7 . The adjustment of the frequency position of the transmission peak of the atomic filter is realized by adjusting the temperature of the original word bubble inside and the magnetic field.
[0042] image 3 It is a structural schematic diagram of the second embodiment of an external cavity feedback laser immune to temperature and current noise of the present invention. like image 3 As shown, the laser includes: a laser semiconductor diode 1 coated with an anti-reflection film, a collimating lens 2, an atomic filter 3, an external cavity mirror 4 with a piezoelectric ceramic 5, and related control circuits 6, and coupling The output lens 8 constitutes. The functions of the above components are described as follows: the laser semiconductor diode 2 coated with an anti-reflection film emits spontaneous emission fluorescence with a spectral width of the order of nm under the current drive of the control circuit 6 and is collimated by the collimating mirror 2. The spectrum of these fluorescence falls within The light energy within the bandwidth of the atomic filter 3 passes through the atomic filter, and is fed back to the laser semiconductor diode coated with an anti-reflection coating under the reflection of the external cavity mirror 4 to form a stimulated emission laser, which is reflected by the coupling output lens 8 and then output laser7. The control circuit 6 is used to control the temperature and current of the laser semiconductor diode 1 coated with an anti-reflection film, the temperature and magnetic field of the atomic filter 3, the voltage of the piezoelectric ceramic 5, and the frequency stabilization of the laser frequency. The piezoelectric ceramic 5 is used to adjust the cavity length of the external cavity to precisely control the frequency of the output laser 7 .
[0043] Figure 4 It is a structural schematic diagram of the third embodiment of an external cavity feedback laser immune to temperature and current noise of the present invention. like Figure 4 As shown, the laser includes: a laser semiconductor diode 1 coated with an anti-reflection film, a collimating lens 2, an atomic filter 3, an external cavity mirror 4 with a piezoelectric ceramic 5, and related control circuits 6, coupled output The lens 8 and the reflection mirror 9 constitute. The functions of the above components are described as follows: the laser semiconductor diode 2 coated with an anti-reflection film emits spontaneous emission fluorescence with a spectral width of the order of nm under the current drive of the control circuit 6 and is collimated by the collimating mirror 2. The spectrum of these fluorescence falls within The light energy within the bandwidth of the atomic optical filter 3 passes through the atomic optical filter, and is fed back to the laser semiconductor diode coated with an anti-reflection coating under the reflection of the external cavity mirrors 4 and 9 to form the stimulated emission of laser light, which is reflected by the coupling output lens 8 Then output the laser 7. The control circuit 6 is used to control the temperature and current of the laser semiconductor diode 1 coated with an anti-reflection film, the temperature and magnetic field of the atomic filter 3, the voltage of the piezoelectric ceramic 5, and the frequency stabilization of the laser frequency. The piezoelectric ceramic 5 is used to adjust the cavity length of the external cavity to precisely control the frequency of the output laser 7 .
[0044] Figure 5 It is a structural schematic diagram of a fourth embodiment of an external cavity feedback laser immune to temperature and current noise in the present invention. like Figure 5 As shown, the laser includes: a laser semiconductor diode 1 coated with an anti-reflection film, a collimating lens 2, an atomic filter 3, an external cavity mirror 4 with a piezoelectric ceramic 5, and related control circuits 6, coupled output The lens 8 and the reflection mirror 9 constitute. The functions of the above components are described as follows: the laser semiconductor diode 2 coated with an anti-reflection film emits spontaneous emission fluorescence with a spectral width of the order of nm under the current drive of the control circuit 6 and is collimated by the collimating mirror 2. The spectrum of these fluorescence falls within The light energy within the bandwidth of the atomic optical filter 3 passes through the atomic optical filter, and is fed back to the laser semiconductor diode coated with an anti-reflection coating under the reflection of the external cavity mirrors 4 and 9 to form the stimulated emission of laser light, which is reflected by the coupling output lens 8 Then output the laser 7. The control circuit 6 is used to control the temperature and current of the laser semiconductor diode 1 coated with an anti-reflection film, the temperature and magnetic field of the atomic filter 3, the voltage of the piezoelectric ceramic 5, and the frequency stabilization of the laser frequency. The piezoelectric ceramic 5 is used to adjust the cavity length of the external cavity to precisely control the frequency of the output laser 7 .
[0045] Specifically, the semiconductor laser tube used in an external cavity feedback laser immune to temperature and current noise in the embodiment of the present invention is characterized by being coated with an anti-reflection film. The essential difference of the external cavity feedback laser of atomic filter mode selection. In addition, the present invention is not limited to the semiconductor as the gain medium, but also includes other solid gain mediums coated with an anti-reflection film on the end face. The present invention is not limited to a specific alkali metal gas atomic spectrum line, but is applicable to all possible spectral lines corresponding to alkali metal atomic gas filters such as lithium, sodium, potassium, rubidium, and cesium. The atomic optical filter of the present invention also includes a cascaded atomic optical filter formed by combining two atomic bubbles under different temperature and magnetic field conditions. Such a cascaded atomic optical filter has only one frequency transmission peak.
[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it still Modifications or equivalent replacements can be made to the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.
