CN105954831B - A kind of fiber bragg grating with temperature memory - Google Patents
A kind of fiber bragg grating with temperature memory Download PDFInfo
- Publication number
- CN105954831B CN105954831B CN201610227564.8A CN201610227564A CN105954831B CN 105954831 B CN105954831 B CN 105954831B CN 201610227564 A CN201610227564 A CN 201610227564A CN 105954831 B CN105954831 B CN 105954831B
- Authority
- CN
- China
- Prior art keywords
- grating
- temperature
- reflection
- wavelength
- fiber bragg
- 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
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02057—Optical fibres with cladding with or without a coating comprising gratings
- G02B6/02076—Refractive index modulation gratings, e.g. Bragg gratings
- G02B6/02195—Refractive index modulation gratings, e.g. Bragg gratings characterised by means for tuning the grating
- G02B6/02204—Refractive index modulation gratings, e.g. Bragg gratings characterised by means for tuning the grating using thermal effects, e.g. heating or cooling of a temperature sensitive mounting body
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
Abstract
The invention discloses a kind of fiber bragg grating with temperature memory function, the Bragg-grating structure of fiber core is formed on including one section of optical fiber and writing.The fiber bragg grating has two reflection peak line structures for corresponding respectively to secondary grating and IIa type grating, and the highest ambient temperature value that bimodal wavelength difference lives through it has memory function;The memory function of the bimodal wavelength difference is only related with environment temperature, therefore can exclude the cross sensitivity of the parameters such as strain, lateral pressure;The fiber bragg grating can realize memory function under high temperature environment.
Description
Technical field
The present invention relates to optical fiber grating sensing field, especially a kind of optical fiber Bragg light with temperature memory function
Grid.
Background technique
Fiber bragg grating (fiber Bragg grating, FBG) is that a kind of fibre core becomes with periodic refractive index
There is the optical fiber photonics passive device of change electromagnetism interference, flexible structure, optical fiber compatibility, Wavelength-encoding, spectral line to be simply easy to
Demodulation, the features such as multiplexing capacity is strong, structure simple easy to make, compact, obtain in Fibre Optical Sensor and the communications field
It is widely applied.
Due to the thermo-optic effect and thermal expansion effects of optical fiber, the Bragg reflection wavelength of fiber bragg grating can be corresponding
It changes, therefore, by wavelength-temperature one-to-one relationship, FBG may be implemented for the sensing function of environment temperature.
In the correlative study of FBG temperature sensing, it is broadly divided into three aspects:
One, the enhanced sensitivity of temperature sensing sensitivity: high thermal expansion coefficient material can be coated by surface, in high thermo-optical coeffecient
FBG processed is write on optical fiber to realize;
Two, strain in temperature sensing, pressure such as bring at the elimination of cross sensitivities: can be by reference to FBG, polarization is bimodal
FBG, the modes such as Harmonic Method are realized;
Three, it improves the heat-resisting ability of fiber bragg grating: II type grating, IIa type grating, reproduced light can be passed through
The modes such as grid, special doped fiber grating are realized.
Aforesaid way is provided to FBG to the sensing function of temperature, focuses mainly on FBG for the sound of variation of ambient temperature
It should and realize real-time monitoring, and the transducing signal of FBG itself for environment temperature and does not have Memorability.Therefore, actual
Measurement and data processing are generally required in while being carried out, this just needs to be equipped in sensing process at a whole set of data demodulation
Reason system.However, the mode of this real-time monitoring just will receive biggish limitation, such as field detection, pole in certain applications
Detection etc. under end ring border.
Summary of the invention
It is bimodal using its main purpose of the present invention is to provide a kind of fiber bragg grating with temperature memory
The highest ambient temperature value that the method for wavelength difference lives through it realizes the function of saving with record, moreover, this wavelength
The memory function of difference is only related with environment temperature, therefore can exclude the cross sensitivity of the parameters such as strain, lateral pressure.
The purpose of the present invention is realized by the following technical solution: a kind of optical fiber Bragg light with temperature memory
Grid, the IIa type fiber bragg grating (rear abbreviation " secondary-IIa grating ") with secondary grating, reflection spectral line has bimodal
Structure, respectively secondary grating and IIa type optical grating constitution, secondary optical grating reflection peak are located at the short wavelength at IIa type optical grating reflection peak
Direction.This unique Double-peak Phenomenon is unrelated with the birefringent of optical fiber, grating secondary lobe and high-order mode coupling.
The bimodal peak wavelength all has positive response for temperature, and the temperature-responsive at secondary optical grating reflection peak is more
Greatly, with the raising of environment temperature, secondary optical grating reflection peak is presented on wavelength moves closer to becoming for the type optical grating reflection peak IIa
Gesture.When environment temperature is cooled to room temperature, this is bimodal to separate to original state, and wave when being held in maximum temperature
Length is poor, as long as therefore by the trace to bimodal wavelength difference, can obtain the maximum temperature that grating is subjected to, be realized pair with this
The memory function of temperature.
Secondary-IIa the grating is for the specific requirement for writing optical fiber processed: fibre core diameter is necessarily less than 6 microns, excellent
Choosing, be 3 microns, fibre core germanium ion content is greater than 10%.
The production method of the secondary-IIa grating reflector is specifically: using excimer laser combination phase mask
Plate is directly exposed above-mentioned Active Optical Fiber, realizes periodic refractive index modulation.
The quasi-molecule laser source avoids additional optical fiber from carrying hydrogen etc. only with 193 nanometers of UV excimer lasers
Enhanced sensitivity means are realized and are directly inscribed, while can provide biggish space Talbot length.
The phase mask plate can realize the design of optical grating reflection wavelength by changing the period of phase mask plate,
Preferably, optical grating reflection Wavelength design is in C-band.
Transmission spectral line derivation feature of the secondary-IIa grating in exposure modulation are as follows: firstly, nascent grating is with exposure
The accumulation of light quantity, optical grating reflection rate are gradually increased, while the bragg reflection wavelength of grating is just changing to long wave with refractive index
Direction drift, embodies typical I type grating derivation feature.Originally third contact of a total solar or lunar eclipse grid reflectivity close to saturation when, secondary grating start from
It spectrally displays, is located at nascent grating shortwave length direction.Then, after nascent grating reaches saturation, with light exposure after
Continuous accumulation, reflected intensity, which gradually subsides, starts to decay and reach minimum value, and its reflection wavelength still drifts about to long wave direction.?
During this, the reflectivity of secondary grating is gradually increased and to long wave direction movement, and the reflectivity of secondary grating will be more than just
Bireflectance peak structure is presented in third contact of a total solar or lunar eclipse grid.Finally, continuing to build up with light exposure, long wave length direction occur one it is new anti-
Peak is penetrated, and reflection wavelength drifts about to shortwave direction while reflectivity constantly increases, embodies the negative variation of refractive index, be IIa type light
The derivation feature of grid, and secondary optical grating reflection rate continues enhancing and to long wave direction movement, nascent grating subsides completely, therefore shape
At the two peak structure of a new secondary grating-IIa type grating, the reflectivity of secondary grating is better than IIa type grating always, and locates
In shortwave length direction.The wavelength moving direction of two reflection peaks moves towards on the contrary, presenting in the process.The spectral line of grating is most
Whole state is two reflection peaks, has certain wavelength difference.Its wavelength difference initial value depends on cumulative exposure amount and grating is write
The prestressing force at optical fiber both ends is loaded when processed.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1, secondary-IIa type fiber bragg grating of the invention not only has the temperature sensing of traditional Bragg grating
Ability is also equipped with special temperature memory function, therefore can get rid of the demand of complicated monitoring instrument in measurement, reaches survey
Discreteization of amount and data processing, to realize the purpose of portable detection, implementation method is simple, can be applied to field spy
The fields such as survey, aviation safety.
2, the production of secondary-IIa type fiber bragg grating of the invention is without carrying hydrogen and annealing, while the optical fiber
Carrier has the features such as highly doped germanium, small fibre core, has the ability efficiently prepared, more economic benefit.
3, memory function and ring of the bimodal wavelength difference of secondary-IIa type fiber bragg grating of the invention to temperature
Border temperature is related, and the influence of the intrinsic sensitive parameter of the optical fiber such as not strained, lateral pressure avoids cross sensitivity.
4, secondary-IIa type fiber bragg grating of the invention can work normally under high temperature environment.
Detailed description of the invention
Fig. 1 is the structure chart of the secondary-IIa type fiber bragg grating of the embodiment of the present invention 1;
Fig. 2 is that above-mentioned secondary-IIa type fiber bragg grating is covered in 193nm excimer laser combination phase in the present invention
Diaphragm plate write grating transmission spectrum typical case's derivation feature during system;
Fig. 3 is that the above-mentioned secondary-IIa type fibre Bragg grating of the present invention in environment temperature is warming up to certain temperature, then warm
Transmission spectrum comparison after spending the room temperature that cools down back;
Wherein: 1- fiber core;2- fibre cladding;Secondary-IIa type fiber bragg grating the structure of 3-.
Specific embodiment
Present invention will now be described in further detail with reference to the embodiments and the accompanying drawings, but embodiments of the present invention are unlimited
In this.
Embodiment 1
As shown in Figure 1, a kind of fiber bragg grating for realizing temperature memory function, comprising: fiber core 1, and write
Secondary-IIa type fiber bragg grating the structure 2 being formed on fiber core 1;The outside of fiber core 1 is coated with fibre cladding
3。
Representative value is that the diameter of fiber core 1 is 3 microns, and the diameter of fibre cladding 3 is 125 microns, fiber core 1
Germanium ion doping concentration is 10% or more, as long as the diameter of fiber core 1, less than 6 microns, and the germanium ion for meeting fibre core is mixed
The optical fiber of miscellaneous concentration is suitable for the present embodiment.
Secondary-IIa type fiber bragg grating structure 2 is covered using 193 nanometers of UV excimer laser combination phases
Periodic refractive index that diaphragm plate method is formed on fiber core 1 changes and is formed, excimer laser representative value are as follows: repetition rate
200 hertz are set as, laser unit energy is 120 millijoules/square centimeter, and the period of phase mask plate is 1067 nanometers.
As shown in Fig. 2, being the typical derivation transmission spectrum of embodiment 1 in the production process, derivation direction is the " time for exposure
1 " to " time for exposure 5 ".It is characterized in that: firstly, nascent optical grating reflection rate is gradually increased, while the bragg reflection wavelength of grating
It drifts about as refractive index is just changing to long wave direction, embodies typical I type grating derivation feature, be shown in " time for exposure 1 ";When
Close to when being saturated, secondary grating starts to be located at nascent grating shortwave length direction from spectrally displaying nascent optical grating reflection rate,
For shown in " time for exposure 2 ";Then, after nascent grating reaches saturation, reflected intensity, which gradually subsides, to be started to decay and its back wave
Long still to drift about to long wave direction, the reflectivity of secondary grating is gradually increased and to long wave direction movement, in this process, secondary
The reflectivity of third contact of a total solar or lunar eclipse grid will be more than nascent grating, and will appear a new reflection peak in long wave length direction is IIa type grating, such as
Shown in " time for exposure 3 ".Then, nascent grating continues to decay to and be submerged among background power completely, IIa type grating and reflection
Reflection wavelength drifts about to shortwave direction while rate constantly increases, and embodies the negative variation of refractive index, and secondary optical grating reflection rate continues
Enhance simultaneously mobile to long wave direction, form the two peak structure of one new " secondary grating-IIa type grating ", secondary grating it is anti-
It penetrates rate and is better than IIa type grating always, and be in shortwave length direction, in the process the wavelength moving direction phase of two reflection peaks
Instead, oppositeization movement is presented;The spectral line end-state of grating is two reflection peaks, such as shown in " time for exposure 4 ", wavelength difference and
Prestressing force of the load at optical fiber both ends, the representative value of time for exposure when spectral line form writes processed depending on cumulative exposure amount and grating
It is 10 minutes, prestressing force representative value is 0.2 newton.
As shown in figure 3, in embodiment 1, initial bimodal wavelength difference be 0.44 nanometer (room temperature: 25 degrees Celsius) it is secondary-
IIa type fiber bragg grating at various temperatures and returns to the spectral line comparative situation after room temperature.It is Celsius to reach 200 in temperature
When spending, it is 0.42 nanometer that bimodal wavelength difference, which reduces, then when temperature is cooled to room temperature (25 degrees Celsius) again, bimodal wavelength difference according to
Old is 0.42 nanometer, illustrates that 200 degree celsius temperatures are recorded;When temperature reaches 300 degrees Celsius, bimodal wavelength difference reduction is
0.38 nanometer, then when temperature is cooled to room temperature (25 degrees Celsius) again, bimodal wavelength difference is still 0.38 nanometer, illustrates 300
Degree celsius temperature is recorded;When temperature reaches 400 degrees Celsius, it is 0.35 nanometer that bimodal wavelength difference, which reduces, then works as temperature weight
Room temperature (25 degrees Celsius) newly are cooled to, bimodal wavelength difference is still 0.35 nanometer, illustrates that 400 degree celsius temperatures are recorded;Work as temperature
When degree reaches 500 degrees Celsius, it is 0.3 nanometer that bimodal wavelength difference, which reduces, then works as temperature and is cooled to room temperature (25 degrees Celsius) again,
Bimodal wavelength difference is similarly 0.3 nanometer, illustrates that 500 degree celsius temperatures are recorded;It is bimodal complete when temperature reaches 600 degrees Celsius
Full superposition, wavelength difference 0, then when temperature is cooled to room temperature (25 degrees Celsius) again, spectral line shape is identical, and wavelength difference is
0, illustrate that 600 degree celsius temperatures are recorded;
The above embodiment is a preferred embodiment of the present invention, but embodiments of the present invention are not by above-described embodiment
Limitation, other any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present invention,
It should be equivalent substitute mode, be included within the scope of the present invention.
Claims (7)
1. a kind of fiber bragg grating with temperature memory, including fiber core, and write and be formed on fiber core
Secondary-IIa type fiber bragg grating structure, which is characterized in that the secondary-IIa type fiber bragg grating structure has
Bimodal reflection spectral line, and the difference of bimodal wavelength has the function of temperature memory;
The bimodal reflection spectral line corresponds respectively to secondary grating and IIa type grating, and the secondary optical grating reflection peak is located at described
The shortwave length direction at IIa type optical grating reflection peak;
The peak wavelength at the secondary optical grating reflection peak and the IIa type optical grating reflection peak all has positive response for temperature,
And the temperature-responsive at the secondary optical grating reflection peak is greater than the temperature-responsive at the IIa type optical grating reflection peak, while with environment
The trend for moving closer to the IIa type optical grating reflection peak is presented in the raising of temperature, the secondary optical grating reflection peak on wavelength, when
When environment temperature is cooled to room temperature, this is bimodal to separate to original state, and wavelength difference when being held in maximum temperature,
The maximum temperature that grating is subjected to is obtained by the trace to bimodal wavelength difference, and the memory function to temperature is realized with this.
2. a kind of fiber bragg grating with temperature memory according to claim 1, which is characterized in that the light
For long and slender core diameter less than 6 microns, fibre core germanium ion content is greater than 10%.
3. a kind of fiber bragg grating with temperature memory according to claim 1, which is characterized in that described time
Raw-IIa type fiber bragg grating structure uses excimer laser combination phase mask plate, to the fiber core directly into
Periodic refractive index modulation is realized in row exposure.
4. a kind of fiber bragg grating with temperature memory according to claim 3, which is characterized in that the standard
Molecular laser uses 193 nanometers of UV excimer lasers.
5. a kind of fiber bragg grating with temperature memory according to claim 3, which is characterized in that the phase
Position mask plate realizes the design of optical grating reflection wavelength by changing the period of phase mask plate, optical grating reflection Wavelength design in
C-band.
6. a kind of fiber bragg grating with temperature memory according to claim 3, which is characterized in that described right
The fiber core is directly exposed, and realizes the transmission spectral line derivation process in periodic refractive index modulation are as follows: firstly, nascent
With the accumulation of light exposure, optical grating reflection rate is gradually increased grating, at the same the bragg reflection wavelength of grating with refractive index just
Change and drift about to long wave direction, embodies typical I type grating derivation feature, it is secondary when third contact of a total solar or lunar eclipse grid reflectivity approaches saturation originally
Grating starts to be located at nascent grating shortwave length direction from spectrally displaying;Then, after nascent grating reaches saturation, with
Light exposure continues to accumulate, and reflected intensity, which gradually subsides, starts to decay and reach minimum value, and its reflection wavelength is still to long wave
Direction drifts about, and the reflectivity of secondary grating is gradually increased and moves to long wave direction, the reflectivity of secondary grating in the above process
It will be more than nascent grating, bireflectance peak structure is presented;Finally, continuing to build up with light exposure, occurs one in long wave length direction
A new reflection peak, and reflection wavelength drifts about to shortwave direction while reflectivity constantly increases, and embodies the negative variation of refractive index, is
The derivation feature of IIa type grating, and secondary optical grating reflection rate continues enhancing and to long wave direction movement, nascent grating disappears completely
It moves back, forms the two peak structure of a new secondary grating-IIa type grating, the reflectivity of secondary grating is better than IIa type light always
Grid, and it is in shortwave length direction, the wavelength moving direction of two reflection peaks moves towards on the contrary, presenting in the above process, grating
Spectral line end-state be two reflection peaks, have certain wavelength difference, wavelength difference initial value depend on cumulative exposure amount with
And the grating prestressing force of load at optical fiber both ends when writing processed.
7. a kind of fiber bragg grating with temperature memory according to any one of claims 1 to 6, feature exist
In being coated with fibre cladding outside the fiber core.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201610227564.8A CN105954831B (en) | 2016-04-13 | 2016-04-13 | A kind of fiber bragg grating with temperature memory |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201610227564.8A CN105954831B (en) | 2016-04-13 | 2016-04-13 | A kind of fiber bragg grating with temperature memory |
Publications (2)
Publication Number | Publication Date |
---|---|
CN105954831A CN105954831A (en) | 2016-09-21 |
CN105954831B true CN105954831B (en) | 2019-02-12 |
Family
ID=56917530
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201610227564.8A Active CN105954831B (en) | 2016-04-13 | 2016-04-13 | A kind of fiber bragg grating with temperature memory |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN105954831B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111051843B (en) * | 2017-07-20 | 2022-03-18 | 英国电讯有限公司 | Optical fiber |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1624443A (en) * | 2004-11-17 | 2005-06-08 | 中国科学院上海光学精密机械研究所 | Long period optical fiber grating temperature sensor |
GB2378259B (en) * | 2001-07-02 | 2005-08-03 | Jds Uniphase Corp | Long period Fiber bragg grating fabrication method |
CN2916581Y (en) * | 2006-05-31 | 2007-06-27 | 中国科学院上海光学精密机械研究所 | Optical fiber Bragg grating sensing device for eliminating cross sensitivity |
CN102721665A (en) * | 2012-05-16 | 2012-10-10 | 暨南大学 | Micro nano optical fiber grating refractive index sensor |
CN204924297U (en) * | 2015-09-17 | 2015-12-30 | 西安科技大学 | Fiber grating temperature and humidity sensor |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1195582A1 (en) * | 2000-10-09 | 2002-04-10 | Eidgenössische Technische Hochschule Zürich | Fiber optic sensor with an optical resonator |
CA2740372C (en) * | 2010-06-01 | 2019-07-02 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Industry Through The Communications Research Centre Canada | Method and system for measuring a parameter in a high temperature environment using an optical sensor |
-
2016
- 2016-04-13 CN CN201610227564.8A patent/CN105954831B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2378259B (en) * | 2001-07-02 | 2005-08-03 | Jds Uniphase Corp | Long period Fiber bragg grating fabrication method |
CN1624443A (en) * | 2004-11-17 | 2005-06-08 | 中国科学院上海光学精密机械研究所 | Long period optical fiber grating temperature sensor |
CN2916581Y (en) * | 2006-05-31 | 2007-06-27 | 中国科学院上海光学精密机械研究所 | Optical fiber Bragg grating sensing device for eliminating cross sensitivity |
CN102721665A (en) * | 2012-05-16 | 2012-10-10 | 暨南大学 | Micro nano optical fiber grating refractive index sensor |
CN204924297U (en) * | 2015-09-17 | 2015-12-30 | 西安科技大学 | Fiber grating temperature and humidity sensor |
Non-Patent Citations (2)
Title |
---|
High-temperature-resistant chemical composition Bragg gratings in Er 3+-doped optical fiber;S.Trpkovski等;《Optics letters》;20050315;第30卷(第6期);全文 * |
Type IIa Bragg grating based ultra-short DBR fiber laser with high temperature resistance;YANG RAN等;《optics letters》;20151203;第40卷(第24期);第5706-5709页 * |
Also Published As
Publication number | Publication date |
---|---|
CN105954831A (en) | 2016-09-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Frazão et al. | Applications of fiber optic grating technology to multi-parameter measurement | |
Rego | Arc‐Induced Long Period Fiber Gratings | |
Rao | In-fibre Bragg grating sensors | |
Liao et al. | Review of femtosecond laser fabricated fiber Bragg gratings for high temperature sensing | |
Huang et al. | Fiber laser based on a fiber Bragg grating and its application in high-temperature sensing | |
Wang et al. | Femtosecond laser fabrication of nanograting-based distributed fiber sensors for extreme environmental applications | |
Popov et al. | Optical fibres and fibre tapers with an array of Bragg gratings | |
Zhang et al. | Simultaneous measurement of curvature and temperature based on LP11 mode Bragg grating in seven-core fiber | |
Zhang et al. | Microfiber Fabry–Perot interferometer for dual-parameter sensing | |
Harun et al. | Dual wavelength erbium-doped fiber laser using a tapered fiber | |
Skvortsov et al. | FBG array-based random distributed feedback Raman fibre laser | |
CN105954831B (en) | A kind of fiber bragg grating with temperature memory | |
Mihailov | Femtosecond laser-inscribed fiber Bragg gratings for sensing applications | |
Dong et al. | Enhanced high temperature properties of overexposed FBG fabricated by femtosecond laser | |
Li et al. | Tilted fiber Bragg grating in graded-index multimode fiber and its sensing characteristics | |
Yang et al. | 1.3 and 1.55$\mu {\rm m} $ Thermally Regenerated Gratings in Hydrogenated Boron/Germanium Co-Doped Photosensitivity Fiber | |
Dash et al. | Micro-air cavity incorporated tapered-tip photonic crystal fiber based compact refractometer | |
Xin et al. | Sensing Characteristics of Side‐Hole Fiber‐Based Long‐Period Grating | |
Tian et al. | Microfiber Bragg grating for temperature and strain sensing applications | |
Mihailov | Ultrafast laser inscribed fiber Bragg gratings for sensing applications | |
Liu et al. | FPI-based fibre-optic sensor fabricated by excimer laser micromachining and fusion splicing HCF for multi-parameter measurements | |
Sengupta | Fiber Bragg grating sensors and interrogation systems | |
Libish et al. | Design and development of fiber grating based chemical and bio-sensors | |
Huang et al. | Fiber Bragg grating sensors written by femtosecond laser pulses in micro-structured fiber for downhole pressure monitoring | |
Potter et al. | Photosensitive and rare-earth doped ceramics for optical sensing: A review |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |