Development of a Temperature-Controlled Optical Planar Waveguide Sensor with Lossy Mode Resonance for Refractive Index Measurement
Round 1
Reviewer 1 Report
In this work, the authors report an investigation about a planar lossy mode resonance (LMR) sensor with ITO film. The authors investigated refractive index sensitivity and temperature sensitivity when the temperature of the analyte (water or glycerol) deposited on the sensor substrate is changed by applying a voltage to the ITO film.
Unfortunately, I cannot recommend the publication of this work in current state due to the following reasons:
- The paper would benefit of a review of the use of English language, especially concerning the Introduction section.
- The paper lacks novelty, the authors investigated the LMR wavelength shift as a function of the temperature, which changes the thermo-optic coefficient of the analyte. This principle is very well known and investigated also regarding other types of optical sensors. Moreover, inducing the temperature change in the analyte by applying a voltage to the ITO (which is conductive) is also not a novel method.
- The authors have not studied the temperature sensitivity of the device without any analyte. Is this contribution relevant to the sensor overall response? How much?
- The results are not compared with existing literature in order to illustrate the novelty.
- The aim of the paper is not completely clear, especially regarding the possible applications of such device with associated advantages and drawbacks. For example, it’s not clear if the authors want to use the device the measure the temperature or to induce a temperature change in the analyte.
- Overall, the paper needs serious rewritten in order to highlights my doubts.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors propose a LMR sensor with temperture control as refractometer. The reference list need to be increase. The results are poor and not show the temperature control sensor.
Specific comments:
- The title need to be changed. The authors need to be include that the sensor is a waveguide.
- The introduction is complete, however is necessary introduce more references.
- The authors need provide the parameters of sensor head: the tickness of the film, dimension of waveguide. One draw of this sensor head help
- The section 3 is confuse. The authors propose a sensor with temperture control but not show this. Why this study?
- When the authors introduce voltage in the ITO the temerature increase and introduce also a strain. How sove this problema? This strain is important for the final results?
- The results in figure 8 is typical for a study to heat tranfer. What is the information that the authors obtain?
- The authors propose a temperature control but don’t show this. In fact the author made a several study with temperature but not compensate the possible changes in temperature. Why not present the response external refractive índex for different temperatures? The efect os temperture is important
- Some dynamic test i salso necessary with change in temperture and external refractive índex.
The manuscript need to be changed. The authors need provide a new version before a final decision. Thus i recommend a major review and submit a new version
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Remarks for the manuscript ID: Photonics-1236814 entitled "A Temperature-Controlled Lossy Mode Resonance Sensor as a Refractometer"
The paper reports on properties of the temperature-controlled lossy mode resonances (TC-LMR) sensor that uses an indium tin oxide ITO deposited on an optical planar waveguide and a pair of heating electrodes to apply an external voltage. The paper presented new results and it is well written. I have only the following minor questions and comments:
On line 48 is mention: Many other materials can also be used to moderate optical losses, so LMR-based optical fiber sensors are used in physical, chemical, and biomedical fields [9-13]. I recommend replacing the word field with the word sensors.
On line 132 is mention An optical fiber patchcord with an FC connector from a light source was inserted into a hole at the left side of the platform and another optical fiber patch-cord with an SMA connector was inserted into the right side, which links to a spectrometer.
I would like to ask you to provide a description of this fiber.
On line 169 Fig. 2 are presented the time courses for temperature difference as a function of heating time using an applied voltage of 1 V, 4 V, and 8 V for water and glycerol. I would like to ask you why the maximum applied voltage was used 8 V?
On line 256 equation 4. I would like to ask you to provide the definition for parameter ?e and comments for the difference with parameter ?? (the specific heat capacity)?
I recommend providing the description of ATOAGO hand-held refractometer R5000 in chapter 2. Materials and Methods and I would like to ask you how wavelengths were used for refractive index measurement and provide information about the accuracy of measurement?
Final statement
The paper presented new results and it is well written. I recommend doing only minor revisions before accepting the paper for publication.
Minor suggestions
Line 9 The generation of lossy mode resonances (LMR) with metallic oxide film deposited on optical fiber has attracted attention of many applications. - The generation of lossy mode resonances (LMR) with metallic oxide film deposited on optical fiber has attracted the attention of many applications.
Line 10 However, a LMR-based optical fiber sensor is frangible so it does not allow the control of temperature and is not suited to mass production - However, an LMR-based optical fiber sensor is frangible so it does not allow the control of temperature and is not suited to mass production
Line 22 heat transfer mechanism for flat model - heat transfer mechanism for the flat model
Line 33 The optical spectrum of a SPR sensor is highly sensitive to the surrounding medium. - The optical spectrum of an SPR sensor is highly sensitive to the surrounding medium.
Line 37 However, the sensitivity limit for SPR sensors has been reached [5]. - However, the sensitivity limit for SPR sensors have been reached [5].
Line 58 An optical planar waveguide is an alternative to optical fiber for a LMR-based sensor because it is easier to handle, more robust, and involves less cost [19-21]. - An optical planar waveguide is an alternative to optical fiber for an LMR-based sensor because it is easier to handle, more robust, and involves less cost [19-21].
Line 114 Each magnetron had a 3-zone gas distribution system with a manual needle valve, to allow uniform adjustment. Each magnetron was powered by a 10 kW DC power supply. - Each magnetron had a 3-zone gas distribution system with a manual needle valve, to allow uniform adjustment and magnetrons were powered by a 10 kW DC power supply.
Line 124 A typical optical transmission measurement setup was used to measure the spectra that is transmitted through the sensor. - A typical optical transmission measurement setup was used to measure the spectra that are transmitted through the sensor.
Line 128 A schematic diagram of the details of the experimental setup and a photograph of the TC-LMR sensor with the alignment bulk platform are shown in Figure 1 - A schematic diagram of the details of the experimental setup and a photograph of the TC-LMR sensor with the alignment bulk platform is shown in Figure 1.
Line 132 An optical fiber patchcord with a FC connector from a light source was inserted into a hole at the left side of the platform and another optical fiber patch-cord with a SMA connector was inserted into the right side, which links to a spectrometer. - An optical fiber patchcord with an FC connector from a light source was inserted into a hole at the left side of the platform and another optical fiber patch-cord with an SMA connector was inserted into the right side, which links to a spectrometer.
Line 134 The cables were fixed at both ends of the glass and were connected to a LPS-305 power supply (USED-EQUIP CO., LTD, Taipei Taiwan). - The cables were fixed at both ends of the glass and were connected to an LPS-305 power supply (USED-EQUIP CO., LTD, Taipei Taiwan).
Line 148 The resistance of the ITO film material is 42.6 Ω. This is calculated by measuring the resistance between the silver paste electrodes. - The resistance of the ITO film material was 42.6 Ω. This value was calculated by measuring the resistance between the silver paste electrodes.
Line 196 which is defined using Equation(3) - which is defined using Equation (3)
Line 274 the supplied electric power also increases slightly and the thermal equilibrium temperature increases slightly - the supplied electric power also increases slightly and the thermal equilibrium temperature increases slightly.
Line 290 P1 is the transmitted spectrum with analyte. - P1 is the transmitted spectrum with the analyte.
Line 298 An analyte with a RI of 1.3590 results in a LMR wavelength of 871.5 nm. - An analyte with a RI of 1.3590 results in an LMR wavelength of 871.5 nm.
Line 304 The performance of a LMR sensor is evaluated in terms of its sensitivity, - The performance of an LMR sensor is evaluated in terms of its sensitivity,
Line 314 For a ZnO thin film, the sensitivity of a LMR sensor was experimentally determined to be around 760 nm/RIU for a RI of 1.433 [31]. - For a ZnO thin film, the sensitivity of an LMR sensor was experimentally determined to be around 760 nm/RIU for a RI of 1.433 [31].
Line 343 there is theoretical shift in the LMR wavelength of -4.26 nm and -7.45 nm. - there is the theoretical shift in the LMR wavelength of -4.26 nm and -7.45 nm.
Line 410 The results show that the use of an external voltage significantly increases the performance of a LMR sensor - The results show that the use of an external voltage significantly increases the performance of an LMR sensor
Line 420 This research was partial funded by the Ministry of Science and Technology, grant number: MOST 108-2221-E-130-014. - This research was partially funded by the Ministry of Science and Technology, grant number: MOST 108-2221-E-130-014.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have provided satisfactory replies to the comments provided by the authors.
Reviewer 2 Report
I agree with the response of authors, however the need include the figures B1, b2 and b3 from response in the manuscript.
