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Showing papers on "Fiber Bragg grating published in 1988"


BookDOI
01 Jan 1988
TL;DR: Optical Fiber-Chemical Sensing using Direct Spectroscopy Chemical Sensing Using Indicator Dyes Dynamic Light Scattering Applied and Its Application in Concentrated Suspensions In Vivo Medical Sensors Fiber-Optic Gyros Fiber Optic Sensors for Condition Monitoring and Engineering Diagnostics Sensors in Industrial Systems Distributed Sensors as discussed by the authors.
Abstract: Optical Fiber-Chemical Sensing Using Direct Spectroscopy Chemical Sensing Using Indicator Dyes Dynamic Light Scattering Applied and Its Application in Concentrated Suspensions In Vivo Medical Sensors Fiber-Optic Gyros Fiber-Optic Sensors for Condition Monitoring and Engineering Diagnostics Sensors in Industrial Systems Distributed Sensors -- Recent Developments Multiplexing Techniques for Fiber-Optic Sensors Fiber Optics and Smart Structures Fiber-Optic Sensors -- Commercial Presence

364 citations


Proceedings ArticleDOI
27 Jan 1988
TL;DR: In this paper, Bragg gratings can be created in photo-refractive germanosilicate fiber by lateral exposure of the core to an ultraviolet two-beam interference pattern at a wavelength which lies in the 244.5 nm band.
Abstract: In 1978. K. O. Hill and colleagues1 reported the formation of refractive index gratings in germanosilicate core, silica clad fibers by injection of 488 and 514.5 nm argon-ion laser radiation into one end of the core. A few years later, Lam and Garside2 showed the grating strength increased as the square of the power flux, suggesting a two-photon process as responsible for the photo-induced changes. Quite apart from these experiments, other researchers3–4 observed in fused germania and germania-doped silicate glasses the presence of an intense UV absorption band at 244.5 nm thought to be due to oxygen vacancy defects. Our experiments show that Bragg gratings can be created in photo-refractive germanosilicate fiber5 and in specially prepared germania wafers by lateral exposure of the core to an ultraviolet two-beam interference pattern at a wavelength which lies in the 244.5 nm band. It is believed that the index changes are due to the bleaching of this band. This paper describes these experiments and presents measurements of the in-fiber filter characteristics obtained by the two-beam holographic exposure method. We discuss and illustrate how the gratings can be used to form wavelength-selective, tandem temperature and strain sensing regions in a single fiber.

176 citations


Patent
27 Dec 1988
TL;DR: In this paper, the effect of the gratings and of the sensing length on the wavelengths of the light emerging from one of the end portions of the optical fiber is detected, where resonant buildup of light at certain wavelengths that are located within the stopband range and depend on the length of sensing portion as influenced by changes in the monitored parameter takes place.
Abstract: An arrangement for sensing changes in a monitored parameter includes an optical fiber which has at least one sensing fiber length including a sensing portion situated at a monitoring location of a body. Two periodic gratings of the same periodicity are situated in the fiber each at a different end of the sensing fiber length. Such gratings are reflective to a predominant portion of any light that propagates in the fiber and has a wavelength in a stopband range around twice the periodicity. When broadband coherent light including sensing light with wavelengths within the stopband range is launched into a first end of the optical fiber for propagation longitudinally of the fiber toward a first of the gratings, the predominant portion of the sensing light is reflected from the first grating and the remainder of the sensing light passes into the sensing fiber length, where resonant buildup of light at certain wavelengths that are located within the stopband range and depend on the length of the sensing portion as influenced by changes in the monitored parameter takes place, and the gratings are rendered substantially transparent to the sensing light at the plurality of wavelengths following the buildup. The effect of the gratings and of the sensing length on the wavelengths of the light emerging from one of the end portions of the optical fiber is then detected.

67 citations


Patent
22 Feb 1988
TL;DR: In this paper, the authors proposed a wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens.
Abstract: A wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens. The optical path lengths reduce losses due to angular acceptance mismatch in the multiplexer. Close orientation of the fiber array about the optical axis and the use of a holographic dispersion grating reduces other losses in the system. Multi-exposure holographic dispersion gratings enable the multiplexer/demultiplexer for extremely broad-band simultaneous transmission and reflection operation. Individual Bragg plane sets recorded in the grating are dedicated to and operate efficiently on discrete wavelength ranges.

52 citations


Patent
12 Apr 1988
TL;DR: In this article, a test fiber is spliced between a launch fiber and a termination fiber which is provided with a reflective coating at its terminal end, and the forward trace signal and reverse trace signal from the light pulse are detected.
Abstract: A simultaneous bi-directional OTDR optical fiber measurement method wherein a test fiber is spliced between a launch fiber and a termination fiber which is provided with a reflective coating at its terminal end. A laser light pulse is introduced into the launch fiber and the forward trace signal and reverse trace signal from the light pulse are detected. A correction is applied to the reverse trace signal to account for reflectivity originating at the fiber input end so that an accurate measurement can be made of certain fiber characteristics of a single-mode optical fiber.

34 citations


Patent
Wayne V. Sorin1
20 Jan 1988
TL;DR: In this article, a broadband-tunable external fiber-cavity laser system includes a laser diode and a singlemode optical fiber with an in-line fiber optic grating filter, which includes a grating with divergent ridges so that the periodicity at an exposed evanescent field can be adjusted by translating the grating transversely with respect to the fiber.
Abstract: A broadband-tunable external fiber-cavity laser system includes a laser diode, and a single-mode optical fiber with an in-line fiber optic grating filter. The grating filter includes a grating with divergent ridges so that the periodicity at an exposed evanescent field can be adjusted by translating the grating transversely with respect to the fiber. The evanescent field of light transmitted along the fiber core is accessed at a side-polished region. The laser preferentially oscillates at the reflected wavelength, so that the laser output is tuned by moving the grating. The grating is manufactured by oblique exposure to a holographic wavefront, producing the divergent pattern.

34 citations


Patent
06 Jan 1988
TL;DR: In this article, a fiber optic sensor array (10) comprises a single transmit optical fiber (14) for guiding an incident optical signal through a plurality of sensing segments (20A, 20B, 20C) arranged in a series array.
Abstract: A fiber optic sensor array (10) comprises a single transmit optical fiber (14) for guiding an incident optical signal through a plurality of sensing segments (20A, 20B, 20C) in the transmit optical fiber (14) arranged in a series array. The sensor array (10) may include a single return optical fiber (16), or the sensors may be arranged in groups (20A, 202B, 202C) with all the member of one group (202A) being connected to a corresponding return fiber (212). Optical couplers (18A, 18B, 18C) formed between the transmit (14) and return optical fibers (16) couple a portion of the incident signal into the return fiber (16) after the signal propagates through each sensing segment (20A, 20B, 20C). A loop (100A, 100B, 100C) is formed in the transmit fiber at each optical coupler (18A, 18B, 18C) so that the incident signal travels through the sensing segments in one direction and through the return fiber in the opposite direction. The couplers may be identical and may be have either symmetrical or asymmetrical coupling coefficients. Asymmetrical couplers (290, 308, 310) may be used to attenuate the intensities of undesired signals that recirculate in the loops of the array.

34 citations


Journal ArticleDOI
TL;DR: In this article, the first demonstration of Bragg reflector grating filters in Ti: LiNbO3 single-mode channel guides was reported, achieving TE polarisation in Y-cut (X-propagating) material.
Abstract: The first demonstration of Bragg reflector grating filters in Ti: LiNbO3 single-mode channel guides is reported. Filter bandwidths as narrow as 0.14 nm centred at 1.476 μm have been achieved for TE polarisation in Y-cut (X-propagating) material.

33 citations


Journal ArticleDOI
TL;DR: In this article, a very pure single-frequency operation, 10-MHz linewidth, and greatly reduced frequency chirp under direct modulation was obtained by combining a regular Fabry-Perot laser to an external waveguide Bragg reflector.
Abstract: Single-frequency operation of 1.5- mu m semiconductor lasers was obtained by combining a regular Fabry-Perot laser to an external waveguide Bragg reflector. The laser is characterized by very pure single-frequency operation, 10-MHz linewidth, and greatly-reduced frequency chirp under direct modulation. The laser has been tested in 1.7-Gb/s transmission experiments over 82.5 km of fiber. >

32 citations


Journal ArticleDOI
TL;DR: In this article, the coherence length of frequency-doubled light generated in an optical fiber pumped by light at λ = 1.064 μm was measured interferometrically.
Abstract: The coherence length of frequency-doubled light generated in an optical fiber pumped by light at λ = 1.064 μm was measured interferometrically. The largest bandwidth for second-harmonic generation in a fiber was measured to be approximately 3 A. By coupling light at 1.064 and 0.532 μm simultaneously into an unprepared fiber, a dynamic grating was created in the fiber. This grating made it possible to frequency double different wavelengths in the IR region.

31 citations


Journal ArticleDOI
TL;DR: In this article, a distributed feedback structure having a predominant gain at an edge wavelength of the Bragg reflection band is proposed and analytical results are presented, which has both refractive index and gain-loss profiles with the same period.
Abstract: A distributed-feedback structure having a predominant gain at an edge wavelength of the Bragg reflection band is proposed and analytical results are presented. The structure has both refractive-index and gain-loss profiles with the same period. Since the gains per period at two edge wavelengths of this structure is substantially different, the selective amplification at the single wavelength is less sensitive to both fabrication accuracy and matching conditions than other single-wavelength schemes which utilize refractive-index profile alone. >

Patent
31 Aug 1988
TL;DR: In this article, a multi-mode optical sensor and method for optically sensing a physical perturbation includes a multiuser optical fiber segment that accepts coherent monochromatic radiation from a suitable source.
Abstract: A multi-mode fiber optic sensor and method for optically sensing a physical perturbation includes a multi-mode optical fiber segment that accepts coherent monochromatic radiation from a suitable source. As the radiation is propagated in the fiber the various modes form a complex interference pattern that changes in response to a physical perturbation of the fiber. A detector provides an output signal to a signal processor that analyzes the signal as a function of the change in intensity to provide an information signal that is functionally related to the perturbation.

Patent
18 Mar 1988
TL;DR: In this paper, an integrated device for scanning a laser beam, including a substrate (12), an electro-optic waveguide (14), a Bragg grating electrode array (31), in operative contact with the waveguide, and a array of electro-Optic prisms (33), is presented.
Abstract: An integrated device (10) for scanning a laser beam, including a substrate (12). An electro-optic waveguide (14), a Bragg grating electrode array (31) in operative contact with the waveguide, and a array of electro-optic prisms (33). The electrode array (31) includes a plurality of upper grating electrodes (26) and a lower first electrode (32). A voltage potential can be placed across individual upper grating electrodes (26) and the lower electrode (32) to establish up a Bragg grating in a small localized region. This localized Bragg grating diffracts a laser beam carried by the waveguide and creates a spatially-variable diffracted beam (40) which can be continuously scanned by deflecting the diffracted beam (40) with the electro-optic prism array (33). The integrated device can also perform two dimensional scanning by including an array of small period diffraction gratings (61), to diffract the laser beam (24) out of the plane of the waveguide film (14), or an array of hologram facets (51) to map a set of points defined by the hologram facets (51) into a two-dimensional matrix of points.

Journal ArticleDOI
TL;DR: In this article, a distributed thermal sensor formed by inducing a deliberated absorption in an infrared optical fiber is presented, where the increased absorption coefficient αab of this modified fiber determines the linear sensing length of the distributed infrared sensor.
Abstract: A novel concept of a fiber optic distributed sensor is presented. In particular, we describe a distributed thermal sensor formed by inducing a deliberated absorption in an infrared optical fiber. The increased absorption coefficient αab of this modified fiber determines the linear sensing length of the distributed thermal sensor. When part of the modified fiber is heated, infrared radiation is generated in the fiber and transmitted through it to its distal face. Measuring this radiation power with a radiometer, we are able to determine the average spatial temperature distribution along the fiber sensing length.

Patent
11 Jan 1988
TL;DR: In this paper, a high-power, single transverse mode laser operation is achieved in an extended-cavity structure by combining a semiconductor gain medium having a large optical cavity together with a length of single mode optical fiber between first and second reflector surfaces.
Abstract: High-power, single transverse mode laser operation is achieved in an extended-cavity structure by combining a semiconductor gain medium having a large optical cavity together with a length of single mode optical fiber between first and second reflector surfaces. The first reflector surface is formed on an end facet of the semiconductor gain medium; the second reflector surface is formed on an end of the optical fiber. Output power is efficiently coupled from the fiber end of the extended-cavity laser to a standard transmission medium.

Patent
24 Jun 1988
TL;DR: A single mode laser glass fiber showing excellent laser oscillation characteristics even at a short fiber length can be efficiently obtained using a phosphate laser glass with excellent laser characteristics as discussed by the authors, which can be used to construct a single-mode laser sensor.
Abstract: A single mode laser glass fiber showing excellent laser oscillation characteristics even at a short fiber length can be efficiently obtained using a phosphate laser glass with excellent laser characteristics.

Journal ArticleDOI
TL;DR: In this article, a surface-emitting distributed Bragg reflector laser array with three-stripes was fabricated and the external differential quantum efficiency was 32% and the maximum output power was 500 mW.
Abstract: A surface-emitting distributed Bragg reflector laser array with three-stripes were fabricated. The external differential quantum efficiency was 32% and the maximum output power was 500 mW.

Patent
Raman Kashyap1
21 Sep 1988
TL;DR: In this paper, a method of structurally modifying a silica monomode optical fiber by launching optical power into the fiber from an Nd:YAG laser operating at 1.064 μm was proposed.
Abstract: A method of structurally modifying a silica monomode optical fiber (4) by launching optical power into the fiber (4) from an Nd:YAG laser operating at 1.064 μm and raising the temperature of a portion of the fiber (4) by bringing a metal film (12) into contact with a polished half-coupler block (6) to absorb energy from the laser (2). A structural modification of the fiber is initiated which propagates towards the laser (2) sustained by the optical power. It provides a means of decommissioning an optical fiber. The modified optical fiber (4) has regular periodic damage sites which can be used to form a diffraction grating. The method may also be used as an optical power limiter to protect optical networks from too high optical power inputs.

Patent
04 Jul 1988
TL;DR: In this paper, the authors proposed a method to reduce the size and price of the optical fiber type optical demultiplexer by inserting and fixing a wavelength filter in a groove formed in an optical fiber fixed to a substrate at right angles to the fiber axis and providing a photodetector opposite the reflecting surface of the filter.
Abstract: PURPOSE:To reduce the size and price of the optical fiber type optical demultiplexer and to facilitate its assembling operation by inserting and fixing a wavelength filter in a groove formed in an optical fiber fixed to a substrate at right angles to the fiber axis and at 45 deg. to the substrate flank and providing a photodetector opposite the reflecting surface of the filter. CONSTITUTION:The part of the optical fiber 12 where its coating 12a is removed in embedded and fixed in the long groove 11 formed previously in the substrate 10. Then the groove 13 is formed and the wavelength filter 14 is inserted, adhered, and fixed. Then the flank of the fiber 12 is ground nearly to the core together with the substrate and the photodetector 15 is mounted and fixed thereupon. Light beams with wavelengths lambda1 and lambda2 which are incident from an end part 12-1 are propagated in the optical fiber 12 to enter the wavelength filter 14, and while the light with the wavelength lambda1 is reflected and detected by the photodetector 15, the light with the wavelength lambda2 is transmitted through the wavelength filter 13 and projected from the end part 12-2 of the optical filter 12.

Journal ArticleDOI
TL;DR: In this article, a wavelength-locked, AlGaAs channeled-substrate-planar distributed feedback laser has been made that operates to 40 mW pulsed, where the Bragg grating is situated at the shoulders of the layers of AlGaA and GaAs.
Abstract: A wavelength‐locked, AlGaAs channeled‐substrate‐planar distributed feedback laser has been made that operates to 40 mW pulsed. The Bragg grating is situated at the shoulders of the layers of AlGaAs and GaAs. Overall power efficiencies of 15% have been measured at 40 mW of output power.

Journal ArticleDOI
TL;DR: In this article, active mode-locking of an extended-cavity silicon chip Bragg reflector laser has been shown to achieve 27 ps duration at repetition rates up to 7 GHz with a controllable narrow optical spectrum.
Abstract: The authors report active mode-locking of an extended-cavity silicon chip Bragg reflector laser. Pulses of 27 ps duration at repetition rates up to 7 GHz, have been achieved with a controllable narrow optical spectrum. >

Patent
25 Aug 1988
TL;DR: In this article, a plug member with fiber and focusing lens adjustable in the optical axial direction (z-direction) and a supporting tube disposed in the z-direction in front of the lens for an optical glass body is presented.
Abstract: For the transfer of laser light into an optical fiber in such a manipulatorevice a laser beam is made to form a very finely focused spot of light on the end face of an optical fiber. In order to obtain an optimal transfer efficiency the manipulator includes firstly a plug member with fiber and focusing lens adjustable in the optical axial direction (z-direction) and, secondly, a supporting tube disposed in the z-direction in front of the lens for an optical glass body. Said supporting tube is adjustable in x- and y-directions at right angles to the z-axis, against the bias force from a spring member and angularly adjustable in relation to the z-axis.

Patent
01 Dec 1988
TL;DR: In this paper, a rod-type laser light and a back surface of an optical fiber were used to suppress the formation of an interfering standing wave in the laser cavity by preventing light from reflecting back into the cavity from the optical fiber.
Abstract: A system for launching laser (1) into an optical fiber (14), which includes means for suppressing establishment of an interfering standing wave in the laser cavity (6), either by preventing laser (1) light from reflecting back into the cavity from the fiber (14), or by preventing light which does reflect into the cavity from the fiber from establishing an interfering standing wave. In a preferred embodiment, the system includes a rod-type laser light (1) and a back surface (12), and an optical fiber (14) having an end surface (15) substantially parallel to and coupled with the back surface (12) of the lens (10), where the angle between the propagation direction of the incident laser light and the normal to the fiber's end surface (10) is sufficiently large so that reflected light from the lens-fiber interface will propagate away from the laser cavity and will not re-enter the laser cavity. Alternative embodiments include means for varying the optical path length between the laser (1) and the fiber (14), or means for varying the frequency of light propagating between the laser (1) and the fiber (14) in order to reduce the likelihood that light reflected back into the laser (1) from the fiber (14) will establish an interfacing standing wave.

Patent
28 Apr 1988
TL;DR: In this paper, the back Brillouin scattered light generated by a probing light source is taken out by a selecting and taking out device to be detected by a photodetector.
Abstract: PURPOSE:To effectively evaluate an optical fiber characteristic by allowing a probing light from a probing light source to be made incident on an optical fiber to be measured, taking out selectively a generated back Brillouin scattered light and detecting it by a photodetector. CONSTITUTION:A probing light emitted from a probing light source 1 is sent to an optical fiber to be measured and generates a Brillouin scattered light. Subsequently, a back Brillouin scattered light which is scattered in the rear in the optical fiber to be measured 4 is taken out selectively by a selecting and taking out device 6. In this state, an optical demultiplexer 2 couples the probing light from the probing light source 1 to the optical fiber to be measured 4, and also, couples the back Brillouin scattered light generated in the optical fiber to be measured 4 by its probing light to the selecting and taking out device 6. The back Brillouin scattered light which has been fetched by this selecting and taking out device 6 is detected by a photodetector 7, and an electric signal which has been brought to photoelectric conversion is brought to signal processing 8. In such a way, an optical fiber network containing not only a cascaded optical fiber line but also a branch fiber line can be measured and evaluated by separating each optical fiber loss or fault position.

Patent
15 Apr 1988
TL;DR: A fiber optic sensor using the treated coil of optical fiber as a structural support system for the sensor is described in this article, and a method for making such a sensor is presented.
Abstract: A fiber optic sensor using the treated coil of optical fiber as a structural support system for the sensor, and a method for making such a sensor

Patent
26 Dec 1988
TL;DR: In this article, the authors proposed to prevent the generation caused by vibration of a fan motor by providing a laser light source provided separately from a microscope body, an optical fiber placed in an illumination leading-in part of the microscope body and an optical fibre connector constrained so as to be detachably in a position of a laser spot of the laser luminous flux.
Abstract: PURPOSE: To prevent the generation caused by vibration of a fan motor by providing a laser light source provided separately from a microscope body, an optical fiber placed in an illumination leading-in part of the microscope body, and an optical fiber connector constrained so as to be detachably in a position of a laser spot of a laser luminous flux CONSTITUTION: The equipment is provided with a laser light source 26 provided separately from a microscope body 24, a coupling optical system containing a coupling lens 28 for reducing a laser luminous flux emitted from the laser light source 26 in a point shape, and an optical fiber 32 in which one end face 32B is placed in an illuminating light leading-in part 36 of the microscope body 24 Also, the equipment is constituted by providing an optical fiber connector 34 for constraining the other end face 32A of this optical fiber 32 so as to be detachable on a position of a laser spot of the laser luminous flux which is reduced by the coupling lens 28 Accordingly, the laser light source can be changed easily to that of different wavelength, and a transfer of variation of a fan motor in the case when the laser light source of an air-cooling type is used can also be prevented In such a way, the lighting equipment by which the microscope body is not influenced by vibration of the fan motor is obtained COPYRIGHT: (C)1990,JPO&Japio

Patent
13 Dec 1988
TL;DR: In this article, a calibration part for measuring the absolute temperature distribution from the temperature of an optical fiber in a part of the optical fiber to be measured and arranging a temperature sensor in the calibration part is provided.
Abstract: PURPOSE: To miniaturize an entire system and to perform continuous operation by providing a calibration part for measuring the absolute temperature distribution from the temperature of an optical fiber in a part of the optical fiber to be measured and arranging a temperature sensor in the calibration part. CONSTITUTION: Laser pulses oscillated from a laser pulse emitting part 7 are made incident on the optical fiber to be measured 1 through an acoustic optical switch 4. The optical fiber for calibration 2 which is a part of the fiber 1 is incorporated in a heat insulating material 20 which is difficult to accept the variation of external temperature and the temperature sensor 3 is provided to the optical fiber 2. The Raman scattered light generated in the fiber 1 is introduced to a measuring device by a switch 4. In the measuring device, anti-Stokes light in the Raman scattered light is detected by a photoelectric conversion part 5, amplified by an amplifier 6 and transmitted to an AD converter 9. The signal digitized by the converter 9 is averaging-processed in a signal processing part 10 after performing stored measurement about ten thousand times. In such a case, the temperature of the calibration part is measured by the sensor 3 and transmitted to the processing part 10 by switching a switch 8, thereby measuring the absolute temperature distribution. COPYRIGHT: (C)1990,JPO&Japio

Patent
01 Feb 1988
TL;DR: In this paper, an optical fiber end-face mirror is formed at the end face of a remaining part on one end side of all optical fiber coupler so that an induced Raman scattered beam reflected selectively by a variable optical fiber type grating can go back and forth between optical fibre end face mirrors.
Abstract: PURPOSE:To be small-sized, of excellent stability and of enhanced reliability by a method wherein an optical fiber end-face mirror is formed at the end face of a remaining part on one end side of all optical fiber coupler so that an induced Raman scattered beam reflected selectively by a variable optical fiber type grating can go back and forth between optical fiber end-face mirrors. CONSTITUTION:Out of induced Raman scattered beams generated, a beam with a width of 0.01Angstrom is reflected by an optical fiber grating 16 and is incident on a port (3) of an optical fiber coupler 13. The optical fiber coupler 13 transmits almost all of an induced Raman scattered beam in the whole wavelength region from the port (3) to a port (2); 97 % of optical power is reflected by an optical fiber end-face mirror 17 via the port (2) and an optical fiber 14. The reflected beam is transmitter from the port (2) of the optical fiber coupler 13 to the port (3); while it goes back and forth between the optical fiber grating 1 6 and the optical fiber endface mirror 17, it is amplified selectively by a beam from a light source 10, i.e. an excited beam; 3% of the high- intensity and narrow-spectrum induced Raman scattered beam is radiated from the optical fiber end-face mirror 17.

Proceedings Article
11 Sep 1988
TL;DR: In this article, the first demonstration of Bragg reflector grating filters in Ti:LiNbO/sub 3/single mode channel guides is reported, with filter bandwidths as narrow as 0.14 nm centered at 1.476 mu m.
Abstract: The first demonstration of Bragg reflector grating filters in Ti:LiNbO/sub 3/ single mode channel guides is reported. Filter bandwidths as narrow as 0.14 nm centered at 1.476 mu m have been achieved for TE polarization in Y-cut (X-propagating) material. >

Patent
16 Aug 1988
TL;DR: In this paper, a method of determining optical absorption and emission spectra from a crystal or non-crystalline fiber sample is proposed. But the preferred apparatus for carrying out the method includes a broadband light source to generate measurable absorption outside the region of fluorescence and a laser light source for generating measurable absorption in the region in which no fluorescence is present.
Abstract: A method of determining optical absorption and emission spectra from a crystal or non-crystalline fiber sample includes directing a laser light source to a side of the fiber sample and measuring fluorescence intensity at various positions along the crystal fiber sample, and then directing a broadband light source through the ends of the crystal fiber sample and measuring absorption in a region of no fluorescence. The preferred apparatus for carrying out the method includes a broadband light source to generate measurable absorption outside the region of fluorescence and a laser light source for generating measurable absorption in the region of fluorescence.