Development of a Mode-Locked Fiber Laser Utilizing a Niobium Diselenide Saturable Absorber
, Xingxing Li 1, Zhigang Yin 2,4, Hui Ning 1,2, Xin Zhang 1 and Xingwang Zhang 2,4
Round 1
Reviewer 1 Report
This manuscript reports on an Er-doped fiber laser mode-locked by utilizing a niobium diselenide saturable absorber. The preparation process and characterization method of NbSe2 material are clearly described in manuscript. The results show that NbSe2 is a promising photoelectric modulation material due to excellent nonlinear optical properties. I recommended this paper could be published in Photonics with some minor corrections.
1. The saturation intensity and modulation depth of the NbSe2 saturable absorber are given in this manuscript. Please supplement the corresponding nonlinear transmittance diagram of NbSe2 saturable absorber.
2. The time bandwidth product is an important parameter of ultrafast laser. Please calculate and give the time bandwidth product of the mode-locked laser using NbSe2 saturable absorber.
3. Please explain why the NbSe2 material thicknesses measured by atomic force microscope in Fig. 2(c) are different.
4. What is the purpose of sodium dodecyl sulfate and polyvinyl alcohol used in the preparation of NbSe2 material?
5. What the main advantages of NbSe2 compared with other saturable absorbers such as graphene, MXene, metal nanomaterials and heterostructure based saturable absorbers?
Please check the typos in the manuscript.
Author Response
Response to Reviewer 1 Comments
Point 1:The saturation intensity and modulation depth of the NbSe2 saturable absorber are given in this manuscript. Please supplement the corresponding nonlinear transmittance diagram of NbSe2 saturable absorber.
Response 1: The nonlinear transmittance diagram of NbSe2 SA has been supplemented in Fig. 3 (b).
Point 2: The time bandwidth product is an important parameter of ultrafast laser. Please calculate and give the time bandwidth product of the mode-locked laser using NbSe2 saturable absorber.
Response 2: The time bandwidth product has been calculated and added to line 143 of the article
Point 3: Please explain why the NbSe2 material thicknesses measured by atomic force microscope in Fig. 2(c) are different.
Response 3: Liquid phase exfoliation method is an efficient two-dimensional material preparation method. One disadvantage of this method is that the thickness of the prepared material is not uniform, but it is roughly within a range. The thickness of the NbSe2 material prepared in this experiment is about 50 nm.
Point 4: What is the purpose of sodium dodecyl sulfate and polyvinyl alcohol used in the preparation of NbSe2 material?
Response 4: The key of liquid phase exfoliation is to make the surface energy of the material and the solution similar, so that the material can be stripped off. In the experiment, the purpose of using sodium dodecyl sulfate and polyvinyl alcohol in the preparation of the two-dimensional material NbSe2 is to improve the surface energy of the solution as a surfactant and improve the stripping efficiency of the material.
Point 5: What the main advantages of NbSe2 compared with other saturable absorbers such as graphene, MXene, metal nanomaterials and heterostructure based saturable absorbers.
Response 5: NbSe2 has the advantages of large modulation depth, good environmental stability, simple preparation and fast saturation recovery time.
Reviewer 2 Report
In this work, NbSe2 SA was prepared by liquid phase exfoliation, deposited on the end face of the fiber jumper, and and incorporated into the erbium-doped fiber laser. The NbSe2 SA mode-locked laser obtained from this has higher output power and stability, indicating that NbSe2 has excellent nonlinear optical properties and is applied to ultrafast photonic devices. However, there are some problems, which are listed as following. Totally, the paper can be considered for publication after a minor revision.
1) The image pixels must be increased, especially the image in Figure 5 (c) is too blurry.
2) The article mentions that the experimental results of NbSe2 SA mode-locked lasers differ from other reported results based on NbSe2 SA mode-locked lasers. What improvements have been made to achieve higher output power and more stable laser output? And what is the longest time that this stable output state can be maintained?
3) The calculation of time bandwidth product should be given in Figure 5 (c).
4) The TEM of NbSe2 nanosheets should be added in Figure 2.
Author Response
Response to Reviewer 2 Comments
Point 1: The image pixels must be increased, especially the image in Figure 5 (c) is too blurry.
Response 1: Figure 5 has been readjusted.
Point 2: The article mentions that the experimental results of NbSe2 SA mode-locked lasers differ from other reported results based on NbSe2 SA mode-locked lasers. What improvements have been made to achieve higher output power and more stable laser output? And what is the longest time that this stable output state can be maintained?
Response 2: In order to improve the output power and stability of the laser, a new material integration method -- solution dipping method is adopted in this paper. This method makes the material and fiber more closely combined, and the stability of the laser is more than half an hour.
Point 3: The calculation of time bandwidth product should be given in Figure 5 (c).
Response 3: The time bandwidth product has been calculated and is supplemented at line 143 of the article.
Point 4: The TEM of NbSe2 nanosheets should be added in Figure 2.
Response 4: Due to the limitation of experimental conditions, we cannot measure TEM of materials.
Reviewer 3 Report
The authors have successfully demonstrated a stable mode-locking operation in an erbium doped fiber laser by utilizing a NbSe2 saturable absorber. The manuscript is well-written, particularly the introduction section, and the authors have appropriately included relevant references. However, I have a few comments on the manuscript:
1. It is requested to provide figures of higher quality, especially for figure 5.
2. Figure 2 does not appear to show any nanosheet. It would be beneficial to include a high-quality scanning electron microscope (SEM) image to support the authors' claims regarding nanosheets.
3. The authors should emphasize the advantages of the present work compared to similar studies on NbSe2-based saturable absorbers in erbium doped fiber lasers. For instance, a reference such as "Photonics and Nanostructures-Fundamentals and Applications, 54, 101117".
4. It would be valuable to discuss the limitations regarding the central wavelength and whether it can be tuned.
5. In line 100, I was unable to find the experimental results and fittings for the NbSe2 saturable absorber in the manuscript. The authors should ensure that they have included all the relevant experimental data in the manuscript.
The authors have employed proficient English language skills in the manuscript.
Author Response
Response to Reviewer 3 Comments
Point 1: It is requested to provide figures of higher quality, especially for figure 5.
Response 1: Figure 5 has been readjusted.
Point 2: Figure 2 does not appear to show any nanosheet. It would be beneficial to include a high-quality scanning electron microscope (SEM) image to support the authors' claims regarding nanosheets.
Response 2: SEM in Figure 2 is the measurement of NbSe2 nanosheet. Due to the old equipment, the image may not be very clear.
Point 3: The authors should emphasize the advantages of the present work compared to similar studies on NbSe2-based saturable absorbers in erbium doped fiber lasers. For instance, a reference such as "Photonics and Nanostructures-Fundamentals and Applications, 54, 101117".
Response 3: Compared with other fiber lasers based on NbSe2 SA, we use a new integration method to make the material and fiber more closely, and the output power and stability of the laser have been improved accordingly.
Point 4: It would be valuable to discuss the limitations regarding the central wavelength and whether it can be tuned.
Response 4: We are sorry that due to the limitation of experimental conditions, we did not explore the feasibility of tuning the laser center wavelength in the experiment.
Point 5: In line 100, I was unable to find the experimental results and fittings for the NbSe2 saturable absorber in the manuscript. The authors should ensure that they have included all the relevant experimental data in the manuscript.
Response 5: The nonlinear transmittance diagram of NbSe2 SA has been added to Figure 3.
Round 2
Reviewer 2 Report
The author has made reasonable corrections according to the reviewer's opinion and agrees to publish.
Reviewer 3 Report
All of my questions have been addressed by the authors. The current version of the manuscript appears satisfactory.
