CN115764544B - High side mode rejection ratio narrow linewidth external cavity laser and optical equipment - Google Patents
High side mode rejection ratio narrow linewidth external cavity laser and optical equipment Download PDFInfo
- Publication number
- CN115764544B CN115764544B CN202310027069.2A CN202310027069A CN115764544B CN 115764544 B CN115764544 B CN 115764544B CN 202310027069 A CN202310027069 A CN 202310027069A CN 115764544 B CN115764544 B CN 115764544B
- Authority
- CN
- China
- Prior art keywords
- quantum dot
- laser
- photon filter
- external cavity
- gain chip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention relates to the field of semiconductor lasers, in particular to a high side mode rejection ratio narrow linewidth external cavity laser, which constructs a semiconductor laser through coupling integration based on a quantum dot gain chip with wide gain and a photon filter, increases the spectrum beam combining range by using the quantum dot gain chip with wide gain, improves the spectrum beam combining power, and the photon filter is flexibly prepared by adopting a femtosecond laser point-by-point writing technology, wherein the high Q value of an equivalent resonant cavity is used for realizing main mode selection and high mode gain difference, realizes linewidth compression and noise rejection through an optical negative feedback mechanism, and can realize a seed source laser with more wavelengths in a gain range. The invention realizes the laser output with narrow linewidth and high side mode rejection ratio by using the narrow reflection bandwidth and apodization refractive index modulation of the photon filter through the external cavity optical feedback injection locking technology.
Description
Technical Field
The invention relates to the field of semiconductor lasers, in particular to a high side mode rejection ratio narrow linewidth external cavity laser and optical equipment.
Background
High power fiber lasers are widely used in scientific research, industrial processing and other fields due to their excellent beam quality and high operating efficiency properties. It typically employs a Main Oscillating Power Amplification (MOPA) architecture for multi-stage power amplification of a single frequency seed source. And the high-power output of kilowatt level is realized through the spectrum beam combination of the high-power fiber lasers with the multi-channel MOPA structure. The characteristics of laser mode, linewidth, polarization and the like will change in the multi-stage energy amplification process. Therefore, stringent requirements are imposed on the spectral characteristics of single frequency seed sources, including in particular: (1) The narrow linewidth laser output avoids serious spectrum linewidth broadening in the multi-stage energy amplifying process; (2) High Side Mode Suppression Ratio (SMSR) for suppressing background noise of spontaneous emission spectrum in the multi-stage energy amplification process; (3) The low noise and high frequency stability reduce the influence of nonlinear effect and inhibit the line width broadening; (4) broad spectrum beam combining range to increase the beam combining power. A series of lasers of the same wavelength band is therefore required as seed sources to increase the spectral combining range. While the characteristics of the seed source laser, such as its spectrum, beam quality and power level, directly determine the effect of the spectral combining. Therefore, it is necessary to perform line width narrowing and noise suppression of the seed source laser.
Current common schemes for implementing high power fiber laser seed sources mainly include solid state lasers, fiber lasers, and semiconductor lasers. Although solid state lasers and fiber lasers can achieve linewidths on the order of kilohertz (kHz), solid state lasers are bulky, sensitive to shock and vibration, relatively low in stability, and require additional Laser Diode (LD) pumping. While fiber lasers also require LD pumping and their wavelength range is limited by the amplified spontaneous emission spectrum (ASE) of the gain fiber, power consumption, size, cost and noise are all high. The semiconductor laser can effectively avoid the problems through reasonable laser structure design, has the advantages of compact structure, high reliability, photoelectric efficiency and the like, and can be used as a beam combination seed source of a high-power fiber laser. There are also some areas where improvements are needed for semiconductor lasers. Semiconductor lasers of Distributed Feedback (DFB) and Distributed Bragg Reflection (DBR) structures can achieve linewidth output on the order of megahertz (MHz) or less by optimizing their waveguides, grating structures, optical field confinement factors, linewidth broadening factors, and transmission losses; however, this often requires complex epitaxy and device structures, which are technically difficult and costly. While common external cavity semiconductor laser structures, such as etalons, bulk gratings, and diffraction gratings, can significantly reduce linewidths by increasing resonant cavity length and extending photon lifetime, lasers are sensitive to environmental vibrations and have a low level of integration, which can affect their reliability and stability. In contrast, integrated external cavity lasers are popular because of their compact and stable cavity structure and extremely low intensity noise levels; its phase frequency noise level can be further suppressed by external cavity feedback techniques. However, high integration also means complicated process and high cost. Spectral combining often employs a series of seed source lasers, which requires a tradeoff between high integration and low cost.
Disclosure of Invention
In view of this, embodiments of the present invention provide a high side-mode suppression ratio narrow linewidth external cavity laser and an optical device.
In a first aspect, an embodiment of the present invention provides a high side mode suppression ratio narrow linewidth external cavity laser, which includes a quantum dot gain chip, a photon filter, a thermistor, a coupling component, a temperature controller and a butterfly-shaped tube shell, where the photon filter is prepared by using a femtosecond laser point-by-point inscribing technology, the quantum dot gain chip, the photon filter and the thermistor are welded on an upper surface of the heat sink, the heat sink is welded on the upper surface of the temperature controller, one end of the coupling component is in a conical structure, and the light output by the quantum dot gain chip is coupled to the photon filter by using the conical structure, and the quantum dot gain chip, the thermistor and the temperature controller are respectively connected with pins of the butterfly-shaped tube shell and are subjected to butterfly-shaped encapsulation.
As an alternative, the center wavelength of the photon filter is 1080 nm, the period is 1.116 μm, and the photon filter corresponds to the long wave side of the gain spectrum of the quantum dot gain chip.
As an alternative, the coupling assembly employs an optical lens or a tapered fiber lens.
As an alternative scheme, the photon filter performs real-time adjustment of femtosecond laser pulse energy by combining a half wave plate HWP and a polarization beam splitter PBS, and prepares the bias toe photon filter by controlling the displacement of an optical fiber through a program.
As an alternative scheme, the direction of the quantum dot gain chip, which is far away from the photon filter, is taken as the light-emitting direction, the front end surfaces of the quantum dot gain chip are all plated with an anti-reflection (AR) coating, the rear end surfaces are all plated with a low-reflection (LR) coating, and the photon filter has a high-reflectivity structure.
As an alternative, the quantum dot gain chip adopts a quantum well structure or a quantum dot structure.
In a second aspect, an embodiment of the present invention provides an optical device having a high side-mode suppression ratio narrow linewidth external cavity laser as described above.
The high side mode rejection ratio narrow linewidth external cavity laser and the optical device provided by the embodiment of the invention realize a high-integration-level and low-cost spectrum beam combination seed source scheme by constructing the semiconductor laser through coupling integration of the quantum dot gain chip based on wide gain and the photon filter. The wide-gain quantum dot gain chip is used for increasing the spectrum beam combining range and improving the spectrum beam combining power. The photon filter can be flexibly prepared by the femtosecond laser energy adjustment technology without being limited by wave bands, periods and the like and without a large number of photolithography plates, the photon filter is flexibly prepared by the femtosecond laser point-by-point inscription technology, the high Q value of the equivalent resonant cavity is used for realizing main mode selection and high mode gain difference, and the laser realizes line width compression and noise suppression through an optical negative feedback mechanism. According to the requirements of the seed source and the performance of the gain chip, the scheme can realize seed source lasers with more wavelengths in the gain range by representing the laser performance under different gains in the gain spectrum of the chip. The invention realizes the laser output with narrow linewidth and high side mode rejection ratio by using the narrow reflection bandwidth and apodization refractive index modulation of the photon filter through the external cavity optical feedback injection locking technology.
Drawings
FIG. 1 is a schematic diagram of a structure of an external cavity laser with a high side mode rejection ratio and narrow linewidth according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a high side mode rejection ratio narrow linewidth external cavity laser according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of ASE spectrum and I-V-P characteristic curves of a quantum dot gain chip in a narrow linewidth external cavity laser with a high side mode rejection ratio according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of reflection spectra and transmission spectra of photon filters with different center wavelengths in a narrow linewidth external cavity laser with a high side mode rejection ratio according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a laser spectrum in a narrow linewidth external cavity laser with a high side mode rejection ratio according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of an I-V-P characteristic curve, lasing wavelength, SMSR versus current, lasing spectrum versus current for a high side mode rejection ratio narrow linewidth external cavity laser according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of the relationship between the output power and the polarization angle and the relationship between the polarization extinction ratio and the injection current in a narrow linewidth external cavity laser with a high side mode rejection ratio according to an embodiment of the present invention;
FIG. 8 is a schematic diagram of a noise power spectral density and a frequency linewidth of a high side-mode rejection ratio narrow linewidth external cavity laser according to an embodiment of the present invention;
FIG. 9 is a schematic diagram of relative intensity noise in a high side mode rejection ratio narrow linewidth external cavity laser according to an embodiment of the present invention;
fig. 10 is a schematic structural diagram of a high side mode rejection ratio narrow linewidth external cavity laser provided in accordance with embodiment 3 of the present invention;
FIG. 11 is a schematic diagram of a high side mode rejection ratio narrow linewidth external cavity laser according to embodiment 4 of the present invention;
fig. 12 is a schematic structural diagram of a high side mode rejection ratio narrow linewidth external cavity laser provided in accordance with embodiment 5 of the present invention;
fig. 13 is a schematic structural diagram of a high side mode rejection ratio narrow linewidth external cavity laser provided in accordance with embodiment 6 of the present invention;
fig. 14 is a schematic structural diagram of a high side mode rejection ratio narrow linewidth external cavity laser provided in accordance with embodiment 7 of the present invention;
fig. 15 is a schematic structural diagram of a high side mode rejection ratio narrow linewidth external cavity laser provided in accordance with embodiment 8 of the present invention;
fig. 16 is a schematic structural diagram of a high side mode rejection ratio narrow linewidth external cavity laser provided in accordance with embodiment 9 of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
The terms first, second, third, fourth and the like in the description and in the claims and in the above drawings are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments described herein may be implemented in other sequences than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Referring to fig. 1, the embodiment of the invention provides a high side mode rejection ratio narrow linewidth external cavity laser, which comprises a quantum dot gain chip 101, a photon filter 102, a thermistor, a coupling component 103, a temperature controller and a butterfly-shaped tube, wherein the photon filter 102 is prepared by adopting a femtosecond laser point-by-point inscribing technology, the quantum dot gain chip 101, the photon filter 102 and the thermistor are welded on the upper surface of a heat sink, the heat sink is welded on the upper surface of the temperature controller, one end of the coupling component 103 is of a conical structure, the conical structure can be formed by polishing, the light output by the quantum dot gain chip 101 is coupled to the photon filter 102 by utilizing the conical structure, the quantum dot gain chip 101, the thermistor and the temperature controller are respectively connected with pins of the butterfly-shaped tube and are packaged in a butterfly-shaped manner, and the butterfly-shaped tube can be a shell made of metal materials.
In some embodiments, the photon filter 102 may be a fiber optic photon filter, where the photon filter 102 has a center wavelength of 1080 nm, a period of 1.116 μm, and corresponds to the long wave side of the gain spectrum of the quantum dot gain chip 101.
In some embodiments, the coupling assembly employs an optical lens or a tapered fiber lens.
In some embodiments, the photon filter is prepared by combining a half wave plate HWP and a polarization beam splitter PBS to perform real-time adjustment of the femtosecond laser pulse energy and by programming the displacement of the optical fiber.
In some embodiments, the direction of the quantum dot gain chip, which is away from the photonic filter, is taken as the light emitting direction, the front end surfaces of the quantum dot gain chip are all plated with an anti-reflection (AR) coating, the rear end surfaces are all plated with a low-reflection (LR) coating, and the photonic filter has a high-reflectivity structure.
In some embodiments, the quantum dot gain chip employs a quantum well structure or a quantum dot structure.
With reference to fig. 1 and 2, the high side mode rejection ratio narrow linewidth external cavity laser provided in embodiment 1 of the present invention includes a quantum dot gain chip, a photon filter, a tapered fiber lens, a heat sink, and a temperature controller, where the chip can implement a wide gain range, the photon filter prolongs the effective length of the resonant cavity, improves the quality factor Q of the resonant cavity, and plays a role in frequency selection. The high Q of an equivalent Fabry-perot (F-P) resonator achieves a main mode selection and a high mode gain difference. The F-P resonant cavity is equivalent to the optical path from the front end face of the gain chip 101 to the reflection center of the photon filter 102. Light entering the equivalent resonant cavity is fed back through the photon filter 102 and then returned to the quantum dot gain chip 101, the carrier density in the equivalent resonant cavity is changed, and the refractive index of the gain medium is also changed. Thus, the oscillation of the selected mode is gradually intensified and the threshold is lowered, and the 3dB bandwidth of the reflection spectrum of the external cavity FBG needs to be less than twice the longitudinal mode spacing to ensure a single longitudinal mode laser output.
The preparation of the photon filter 102 is implemented by using a femtosecond laser point-by-point inscription technology. By combining the half wave plate HWP and the polarization beam splitter PBS, the real-time adjustment of the femtosecond laser pulse energy is performed, and in order to maintain a high SMSR (Side-mode suppression ratio) after multi-stage power amplification, background noise of the spontaneous emission spectrum needs to be suppressed, and the photon filter 102 is selected as a frequency selection element. Compared with a phase mask and a holographic interferometry, the femtosecond laser direct writing method has the advantages of simple process and low cost, and apodized photon filters with different apodized function distributions can be flexibly prepared. When the photon filter is inscribed, the rotation angle and speed of the HWP are adjusted by controlling the stepping motor through a program, and the laser pulse energy is controlled in real time so that the amplitude of the refractive index modulation accords with the distribution of the apodization function. To ensure high power output of the laser, the photonic filter 102 selects a low reflectivity structure.
The spectrum beam combination needs a series of lasers with the same wave band as a seed source, and the quantum dot gain chip 101 with wide gain can increase the range of the spectrum beam combination and improve the power of the spectrum beam combination. The quantum dot gain chip 101 may be a quantum well structure or a quantum dot structure. The ridge waveguide is bent at an angle near the front facet (the end near the photonic filter 102) to eliminate the effects of the cavity effect. The quantum dot gain chip 101 is coated with a highly reflective HR coating on the back facet (the end remote from the photonic filter 102) to reduce losses in the resonant cavity, lower the threshold and increase the output power. While the front facet is coated with an anti-reflective AR coating to minimize the effect of the die cavity pattern. By matching the external cavity structure and the frequency selective element, when the laser gain reaches a sufficiently high value, the laser output can be achieved at any wavelength within the gain chip gain range.
The laser is packaged in standard butterfly shape to ensure performance of the laser. The quantum dot gain chip 101, the photon filter 102 and the thermistor are welded on the upper surface of a heat sink, the heat sink is welded on the upper surface of a temperature controller, and the temperature controller can adopt a semiconductor refrigerator TEC. The end of the fiber near the gain chip 101 is polished into a tapered structure, that is, the light output by the quantum dot gain chip 101 is coupled to the photonic filter 102 using the tapered structure. The process simplifies the laser housing structure to be isolated from the environment. The electrodes of the quantum dot gain chip 101, the thermistor and the temperature controller are welded with the inner leads of the pins of the tube shell. And finally, butterfly packaging is carried out on each device of the semiconductor laser, so that vibration isolation, sound insulation and thermal isolation of the laser are realized.
Referring to fig. 3, in an embodiment of the present invention, a quantum dot gain chip 101 is used to increase the spectrum combining range, where the quantum dot gain chip 101 has a wide gain characteristic, and the spontaneous emission spectrum is shown in fig. 3. The output power of the quantum dot gain chip 101 is approximately 30 mW, the length L of the quantum dot gain chip 101 is 1.5 mm, and the ridge width w is 5 μm. The ridge waveguide is bent 7 ° near the front end face to eliminate the influence of the cavity effect. The quantum dot gain chip 101 has a highly reflective HR coating of about 90% at the back facet to reduce losses in the resonator, lower the threshold and increase the output power, while the anti-reflective AR coating at the front facet has a reflectivity of less than 0.1% to minimize the effects of the chip cavity mode. According to the requirements of the seed source and the performance of the quantum dot gain chip 101, the embodiment can realize seed source lasers with more wavelengths in the gain range by representing the laser performance of the quantum dot gain chip 101 under different gains in the gain spectrum.
To facilitate an understanding of the high side mode rejection ratio narrow linewidth external cavity lasers provided in embodiments of the present invention, example 1 with a center wavelength of 1030 nm and example 2 with 1080 nm, respectively, are provided.
Referring to fig. 4, the femtosecond laser used to write the photonic filter in embodiment 1 of the present invention has a wavelength of 515 nm and a pulse width of 290 fs. The fiber diameter used was 125. Mu.m, the core diameter was 5.3. Mu.m, and the mode field diameter was 6.2.+ -. 0.3. Mu.m. The phase matching condition of the photon filter is that
Wherein the method comprises the steps ofmIn order to be a diffraction order,λ B as a function of the wavelength(s),n eff in order for the index of refraction to be effective,∧is the filter period. A 3 rd order photonic filter of length 6 mm, period 1.064 μm and wavelength 1030 nm was prepared. In order to ensure the output power of the laser, the photon filtering in embodiment 1The device adopts a low-reflectivity structure, the reflectivity is 30%, and the reflection spectrum and the transmission spectrum of the photon filters with different center wavelengths are shown in fig. 4.
Example 2
As shown in connection with fig. 1, embodiment 2 differs from embodiment 1 in that: the center wavelength of the photon filter 202 is changed. The center wavelength of the photon filter 202 becomes 1080 nm, and the period becomes 1.116 μm corresponding to the long-wave side of the gain spectrum of the gain chip. The structure of embodiment 2 is the same as that of embodiment 1, and fig. 1 (a) is a schematic structural diagram of an external cavity semiconductor laser provided in embodiments 1 and 2 according to the present invention; FIG. 1 (b) is a short apodized index modulated grating structure prepared to demonstrate the flexibility of the femtosecond laser energy adjustment method in which a significant topographical gradient is observed in the microscope field of view; in fig. 1, (c) is the grating structure of the laser used in example 1, which is the refractive index modulation profile of the intermediate region of the photonic filter, because the grating region is long, no significant profile grading can be observed in the microscope field of view.
As shown in connection with fig. 5, both lasers achieve stable single mode characteristics. The highest side mode rejection ratio SMSR of 66.3 dB is reached at 400 mA current.
Referring to fig. 6, fig. 6 (a) and (b) are characteristic curves of I-V-P, fig. 6 (c) and (d) are graphs of lasing wavelength, SMSR and current, fig. 6 (e) and (f) are graphs of lasing spectrum and current, fig. 6 (a) corresponds to example 1, fig. 6 (b) corresponds to example 2, and fig. 6 (a) shows that the threshold current and slope efficiency of the 1030 nm laser provided in example 1 are 70 mA and 0.40W/a, respectively, and the maximum output power at 400 mA is 134.6 mW. Fig. 6 (c) and (e) show the variation of the laser spectrum of the 1030 nm laser with injection current, with a wavelength tuning rate of 1.13 nm/a and a continuous wavelength tuning range of 28.2 pm. In addition, the 1080 nm laser provided in example 2 had a threshold current of 144 mA, a maximum output power of 133.0 mW, and a slope efficiency of 0.51W/a, as shown in fig. 6 (b). The wavelength tuning rate was 1.18 nm/A and the continuous wavelength tuning range was 45.3 pm, as shown in FIGS. 6 (d) and (f).
Bonding ofAs shown in fig. 7, by carefully rotating the polarization controller for one period and recording the power change through the polarization controller, a polar plot of 1030 nm laser output power and rotation angle in example 1 was obtained, as shown in fig. 7 (a). Maximum power measured at 400 mA currentP max And minimum powerP min 113.56 mW and 1.91 mW, respectively, the corresponding PER value is 17.74 dB (per=10log) 10 （P max /P min )). The PER values at different currents are shown in fig. 7 (b). The maximum PER value is 18.68 dB.
As shown in connection with fig. 8, the phase noise power spectral density PSD of the laser is selected to derive line width. Fig. 8 (a) shows the power spectral density of 1030 nm laser and fig. 8 (b) is an evaluation of laser linewidth in the full fourier frequency range based on the integrated frequency noise fluctuating power spectral density of the β -isolated line algorithm. 1030 White noise of nm laser is 82960 Hz 2 The corresponding Lorentz line width is 260.5 kHz and the integral line width is about 180.4 kHz.
As shown in connection with fig. 9, the Relative Intensity Noise (RIN) PSD of the 1030 nm laser was measured. At low frequencies of 1 kHz, the relative intensity noise RIN fluctuates between-137 dBc/Hz and-143 dBc/Hz as the frequency increases. RIN is generally stable between-151 dBc/Hz and-154 dBc/Hz in the high frequency range of about 1 MHz.
Example 3
As shown in fig. 10, embodiment 3 differs from embodiment 1 in that: the coupling mode is changed. At the coupling location of the quantum dot gain chip 301 and the photon filter 302, an optical lens 304 is used instead of a tapered fiber lens. The coupling difficulty is reduced, and the coupling range between the quantum dot gain chip 301 and the photon filter 302 is increased.
Example 4
As shown in connection with fig. 11, embodiment 4 differs from embodiment 1 in that: the coupling position of the quantum dot gain chip 401 and the photon filter 402 adopts a tapered fiber lens 403, and the structure of the photon filter 402 is changed. The real-time adjustment of the femtosecond laser pulse energy is realized by combining a half wave plate HWP and a polarization beam splitter PBS; and (3) the displacement of the optical fiber is controlled by a program, so that the bias toe photon filter is prepared.
Example 5
As shown in fig. 12, the difference between embodiment 5 and embodiment 1 is that: the coupling mode and the structure of the photon filter 502 are changed. At the coupling location of the quantum dot gain chip 501 and the photon filter 502, an optical lens 504 is used instead of a tapered fiber lens. The real-time adjustment of the femtosecond laser pulse energy is realized by combining a half wave plate HWP and a polarization beam splitter PBS; and (3) the displacement of the optical fiber is controlled by a program, so that the bias toe photon filter is prepared.
Example 6
As shown in fig. 13, the difference between embodiment 6 and embodiment 1 is that: by adopting the tapered fiber lens 603, the light emitting direction of the laser, the coating film of the quantum dot gain chip 601 and the structure of the photon filter 602 are changed. Taking the direction of the quantum dot gain chip 601, which is far away from the photon filter 602, as the light emitting direction, the front end surfaces of the quantum dot gain chip 601 are all plated with an anti-reflection (AR) coating, the rear end surfaces are all plated with a low-reflection (LR) coating, and the photon filter 602 selects a high-reflectivity structure.
Example 7
As shown in fig. 14, the difference between embodiment 7 and embodiment 1 is that: the coupling mode, the light emitting direction of the laser, the coating film of the quantum dot gain chip 701 and the structure of the photon filter 702 are changed. At the coupling location of the quantum dot gain chip 701 and the photon filter 702, an optical lens 704 is used instead of a tapered fiber lens. Taking the direction of the quantum dot gain chip 701, which is away from the photonic filter 702, as the light emitting direction, the front end surfaces of the quantum dot gain chip 701 are all plated with an anti-reflection (AR) coating, the rear end surfaces are all plated with a low-reflection (LR) coating, and the photonic filter 702 selects a high-reflectivity structure.
Example 8
As shown in fig. 15, the difference between embodiment 8 and embodiment 1 is that: the tapered fiber lens 803 is used, and the light emitting direction of the laser, the coating film of the gain chip 801 and the structure of the photon filter 802 are changed. Taking the direction of the gain chip 801, which is away from the photonic filter 802, as the light emitting direction, the front end surface of the gain chip 801 is coated with an anti-reflection (AR) coating, the rear end surface is coated with a low-reflection (LR) coating, and the photonic filter 802 selects a high-reflectivity structure. The real-time adjustment of the femtosecond laser pulse energy is realized by combining a Half Wave Plate (HWP) and a Polarization Beam Splitter (PBS); by programming the displacement of the fiber, an apodized photonic filter 802 was prepared.
Example 9
As shown in connection with fig. 16, embodiment 9 differs from embodiment 1 in that: the coupling mode, the light emitting direction of the laser, the coating film of the gain chip 901, and the structure of the photon filter 902 are changed. At the coupling location of the gain chip 901 and the photon filter 902, an optical lens 904 is used instead of a tapered fiber lens. Taking the direction of the gain chip 901, which is away from the photon filter 902, as the light emitting direction, the front end surface of the gain chip 901 is plated with an anti-reflection (AR) coating, the rear end surface is plated with a low-reflection (LR) coating, and the photon filter 902 selects a high-reflectivity structure. The real-time adjustment of the femtosecond laser pulse energy is realized by combining the half wave plate HWP and the polarization beam splitter PBS, and the optical fiber displacement is controlled by a program to prepare the toe-off photon filter.
The coupling integration of the wide gain quantum dot gain chip and the femtosecond apodization photon filter is adopted to prepare the semiconductor laser with narrow linewidth and high SMSR as a seed source of spectrum beam combination. The spectrum beam combination needs a series of lasers with the same wave band, and the mass production can be realized on the premise of not sacrificing the performance of the lasers by adopting a low-cost scheme. With the continuous maturity and perfection of semiconductor gain chip and photon filter preparation technology, external cavity lasers based on photon filters have become a powerful seed source scheme. The invention provides a high-integration, low-cost and high-SMSR and narrow-linewidth external cavity semiconductor laser, can be used as a single-frequency seed source of a spectrum beam combination high-power fiber laser.
The high side mode rejection ratio narrow linewidth external cavity laser provided by the embodiment of the invention constructs a semiconductor laser through coupling integration of a quantum dot gain chip based on wide gain and a photon filter, thereby realizing a high-integration-level and low-cost spectrum beam combination seed source scheme. The wide-gain quantum dot gain chip is used for increasing the spectrum beam combining range and improving the spectrum beam combining power. The photon filter can be flexibly prepared by the femtosecond laser energy adjustment technology without being limited by wave bands, periods and the like and without a large number of photolithography plates, the photon filter is flexibly prepared by the femtosecond laser point-by-point inscription technology, the high Q value of the equivalent resonant cavity is used for realizing main mode selection and high mode gain difference, and the laser realizes line width compression and noise suppression through an optical negative feedback mechanism. According to the requirements of the seed source and the performance of the gain chip, the scheme can realize seed source lasers with more wavelengths in the gain range by representing the laser performance under different gains in the gain spectrum of the chip. The invention realizes the laser output with narrow linewidth and high side mode rejection ratio by using the narrow reflection bandwidth and apodization refractive index modulation of the photon filter through the external cavity optical feedback injection locking technology.
Accordingly, an optical device is provided in the embodiments of the present invention, which has the above-mentioned external cavity laser with a high side mode rejection ratio and a narrow linewidth.
The optical device provided by the embodiment of the invention is coupled with the photon filter through the quantum dot gain chip, different chip cavity surface coating films and photon filter reflecting structures are adopted to respectively realize chip end laser output and filter end output, and the photon filter is enabled to realize different apodization function distribution through the energy adjustment of femtosecond laser.
It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present disclosure may be performed in parallel, sequentially, or in a different order, so long as the desired result of the technical solution of the present disclosure is achieved, and the present disclosure is not limited herein.
The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.
Claims (6)
1. The high side mode rejection ratio narrow linewidth external cavity laser is characterized by comprising a quantum dot gain chip, a photon filter, a thermistor, a coupling component, a temperature controller and a butterfly-shaped tube shell, wherein the photon filter is prepared by adopting a femtosecond laser point-by-point inscription technology, the quantum dot gain chip, the photon filter and the thermistor are welded on the upper surface of a heat sink, the heat sink is welded on the upper surface of the temperature controller, one end of the coupling component is of a conical structure, the light output by the quantum dot gain chip is coupled to the photon filter by utilizing the conical structure, and the quantum dot gain chip, the thermistor and the temperature controller are respectively connected with pins of the butterfly-shaped tube shell and are subjected to butterfly-shaped encapsulation;
the photon filter is used for carrying out real-time adjustment on the femtosecond laser pulse energy by combining a half wave plate HWP and a polarization beam splitter PBS, and the optical fiber displacement is controlled by a program, so that the toe-oblique photon filter is prepared.
2. The high side mode rejection ratio narrow linewidth external cavity laser of claim 1 wherein the photonic filter has a center wavelength of 1080 nm and a period of 1.116 μm and corresponds to the long wave side of the gain spectrum of the quantum dot gain chip.
3. The high side-mode rejection ratio narrow linewidth external cavity laser of claim 1, wherein the coupling element employs an optical lens or a tapered fiber lens.
4. The high side mode rejection ratio narrow linewidth external cavity laser of claim 1, wherein the direction of the quantum dot gain chip away from the photon filter is taken as the light emitting direction, the front end surfaces of the quantum dot gain chip are all plated with an anti-reflection (AR) coating, the rear end surfaces are all plated with a Low Reflection (LR) coating, and the photon filter has a high reflectivity structure.
5. The high side-mode rejection ratio narrow linewidth external cavity laser of claim 1, wherein the quantum dot gain chip adopts a quantum well structure or a quantum dot structure.
6. An optical device having a high side mode suppression ratio narrow linewidth external cavity laser as claimed in any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310027069.2A CN115764544B (en) | 2023-01-09 | 2023-01-09 | High side mode rejection ratio narrow linewidth external cavity laser and optical equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310027069.2A CN115764544B (en) | 2023-01-09 | 2023-01-09 | High side mode rejection ratio narrow linewidth external cavity laser and optical equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115764544A CN115764544A (en) | 2023-03-07 |
| CN115764544B true CN115764544B (en) | 2023-05-12 |
Family
ID=85348771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310027069.2A Active CN115764544B (en) | 2023-01-09 | 2023-01-09 | High side mode rejection ratio narrow linewidth external cavity laser and optical equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115764544B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116487996A (en) * | 2023-06-19 | 2023-07-25 | 中国科学院长春光学精密机械与物理研究所 | High side mode rejection ratio narrow linewidth external cavity laser and optical equipment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101436904A (en) * | 2008-12-16 | 2009-05-20 | 北京科技大学 | Microwave photon filter construction capable of implementing negative coefficient |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2135214T3 (en) * | 1995-03-07 | 1999-10-16 | British Telecomm | TO BE. |
| US7362927B1 (en) * | 2004-06-01 | 2008-04-22 | Oewaves, Inc. | Tunable RF or microwave photonic filters using temperature-balanced whispering gallery mode optical resonators |
| JP2006086228A (en) * | 2004-09-14 | 2006-03-30 | Hamamatsu Photonics Kk | Array for semiconductor laser element |
| JP2007134401A (en) * | 2005-11-08 | 2007-05-31 | Toshiba Corp | Optical gate filter, optical integrated circuit and pulse laser equipment |
| US7627253B1 (en) * | 2006-06-28 | 2009-12-01 | Hrl Laboratories, Llc | RF-photonic transversal filter method and apparatus |
| CN101431109B (en) * | 2008-12-03 | 2010-06-02 | 中国科学技术大学 | One-dimensional silicon/silicon dioxide photon crystal filter |
| CN104932121A (en) * | 2015-06-25 | 2015-09-23 | 天津理工大学 | Microwave photon filter based on multi-wavelength fiber laser and chirp Bragg gratings |
| US10656336B1 (en) * | 2018-11-08 | 2020-05-19 | Luminous Computing, Inc. | Method for phase-based photonic computing |
-
2023
- 2023-01-09 CN CN202310027069.2A patent/CN115764544B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101436904A (en) * | 2008-12-16 | 2009-05-20 | 北京科技大学 | Microwave photon filter construction capable of implementing negative coefficient |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115764544A (en) | 2023-03-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6154480A (en) | Vertical-cavity laser and laser array incorporating guided-mode resonance effects and method for making the same | |
| US5771251A (en) | Optical fibre distributed feedback laser | |
| Chen et al. | Widely tunable single-frequency erbium-doped fiber lasers | |
| US8295320B2 (en) | Achieving low phase noise in external cavity laser implemented using planar lightwave circuit technology | |
| US6580740B2 (en) | Semiconductor laser device having selective absorption qualities | |
| JPS6225481A (en) | Laser oscillator unit | |
| JPH11214799A (en) | Semiconductor laser module | |
| US20080212635A1 (en) | High efficiency distributed feedback (dfb) laser with low-duty cycle grating | |
| US6669367B2 (en) | Optical fiber with mirror for semiconductor laser | |
| CN115764544B (en) | High side mode rejection ratio narrow linewidth external cavity laser and optical equipment | |
| JPH0449793B2 (en) | ||
| JP4950030B2 (en) | Stable laser source with very high relative feedback and narrow bandwidth | |
| EP3211736B1 (en) | Semiconductor laser diode and method of manufacture thereof | |
| US10270224B2 (en) | Angled DBR-grating laser/amplifier with one or more mode-hopping regions | |
| CN112563883A (en) | Integrated external cavity type single-frequency linearly polarized semiconductor laser | |
| JP2006518548A (en) | Apparatus and method for frequency conversion | |
| JP2002280668A (en) | High power, kink-free, single mode laser diode | |
| CN113659429B (en) | Linear polarization narrow linewidth external cavity type semiconductor laser | |
| Yan et al. | Study of the characteristics of 976 nm Bragg grating external cavity semiconductor lasers | |
| US7313159B2 (en) | Apparatus and method for providing a single-mode grating-outcoupled surface emitting laser with detuned second-order outcoupler grating | |
| JP2003515938A (en) | Mode-selective facet layers for pump lasers | |
| US20090310634A1 (en) | Stabilized laser source with very high relative feedback and narrow bandwidth | |
| JP2002374037A (en) | Semiconductor laser module, fiber-optic amplifier using the same and optical communication system | |
| JP2002118325A (en) | Semiconductor laser module and exciting light source using the same | |
| CN116487996A (en) | High side mode rejection ratio narrow linewidth external cavity laser and optical equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |