Abstract: Provided is a polarization independent optical isolator including: wedge-shaped birefringent crystal plates each made of a LiNbO3 single crystal; a Faraday rotator 3 made of a magnetic garnet single crystal; and sapphire single crystal plates 2 and 4 bonded to light transmitting surfaces of the Faraday rotator, respectively. A light transmitting surface of each of the sapphire single crystal plates is formed in such a manner as to be offset from the c-plane of the sapphire single crystal plate. An incident angle ?a of imaginary light 300 on each of the sapphire single crystal plates, and an offset angles ?off of the light transmitting surface from the c-plane of each sapphire single crystal plates are set within predetermined ranges, the imaginary light 300 being represented by a bisector of an angle formed by optical axes of the ordinary ray and the extraordinary ray.

Abstract: Provided is a polarization independent optical isolator including: wedge-shaped birefringent crystal plates each being made of a YVO4 single crystal; a Faraday rotator 3 made of a magnetic garnet single crystal; and sapphire single crystal plates 2 and 4 bonded to light transmitting surfaces of the Faraday rotator, respectively. A light transmitting surface of each of the sapphire single crystal plates is formed in such a manner as to be offset from the c-plane of the sapphire single crystal plate. An incident angle ?a of imaginary light on each of the sapphire single crystal plates, and an offset angles ?off of the light transmitting surface from the c-plane of each sapphire single crystal plates are set within predetermined ranges, the imaginary light being represented by a bisector of an angle formed by optical axes of the ordinary ray and the extraordinary ray.

Abstract: Provided is a polarization independent optical isolator including: wedge-shaped birefringent crystal plates each made of a LiNbO3 single crystal; a Faraday rotator 3 made of a magnetic garnet single crystal; and sapphire single crystal plates 2 and 4 bonded to light transmitting surfaces of the Faraday rotator, respectively. A light transmitting surface of each of the sapphire single crystal plates is formed in such a manner as to be offset from the c-plane of the sapphire single crystal plate. An incident angle ?a of imaginary light 300 on each of the sapphire single crystal plates, and an offset angles ?off of the light transmitting surface from the c-plane of each sapphire single crystal plates are set within predetermined ranges, the imaginary light 300 being represented by a bisector of an angle formed by optical axes of the ordinary ray and the extraordinary ray.

Abstract: Provided is a polarization independent optical isolator including: wedge-shaped birefringent crystal plates each being made of a YVO4 single crystal; a Faraday rotator 3 made of a magnetic garnet single crystal; and sapphire single crystal plates 2 and 4 bonded to light transmitting surfaces of the Faraday rotator, respectively. A light transmitting surface of each of the sapphire single crystal plates is formed in such a manner as to be offset from the c-plane of the sapphire single crystal plate. An incident angle ?a of imaginary light on each of the sapphire single crystal plates, and an offset angles ?off of the light transmitting surface from the c-plane of each sapphire single crystal plates are set within predetermined ranges, the imaginary light being represented by a bisector of an angle formed by optical axes of the ordinary ray and the extraordinary ray.

Abstract: In an in-line optical isolator, a first polarization separation element 91, a Faraday rotator 6 made of a BIG film, and a second polarization separation element 92 are placed in that order. The isolator further includes a first optical fiber collimator 1a being placed at the forward-beam incident side of the first polarization separation element 91 and including a collimating lens 101 and a first optical fiber 31, and a second optical fiber collimator 2a being placed at the forward-beam exit side of the second polarization separation element 92 and including a collimating lens 102 and a second optical fiber 32 connected to a fiber amplifier. Also, an edge filter 100, which transmits light emitted from the first optical fiber 31 and having a wavelength equal to an oscillation wavelength and which reflects light emitted from the first optical fiber 31 and having wavelengths shorter than this wavelength, is placed between the second optical fiber collimator 2a and the second polarization separation element 92.

Abstract: In an in-line optical isolator, a first polarization separation element 91, a Faraday rotator 6 made of a BIG film, and a second polarization separation element 92 are placed in that order. The isolator further includes a first optical fiber collimator 1a being placed at the forward-beam incident side of the first polarization separation element 91 and including a collimating lens 101 and a first optical fiber 31, and a second optical fiber collimator 2a being placed at the forward-beam exit side of the second polarization separation element 92 and including a collimating lens 102 and a second optical fiber 32 connected to a fiber amplifier. Also, an edge filter 100, which transmits light emitted from the first optical fiber 31 and having a wavelength equal to an oscillation wavelength and which reflects light emitted from the first optical fiber 31 and having wavelengths shorter than this wavelength, is placed between the second optical fiber collimator 2a and the second polarization separation element 92.

Abstract: A bidirectional optical module having a device 1 for emitting transmitting signal light, an optical fiber 8 which the transmitting signal light from the device enters, a light-receiving device 9 which light from the optical fiber enters, and a wavelength splitting filter 4. The transmitting signal light emitted from the device is sent forward through the optical fiber, and the receiving signal light is received through the optical fiber. The bidirectional optical module has an optical device (optical isolator) of a reflection polarizer 6 bonded to an end face of the optical fiber, a Faraday rotator 5 disposed integrally on the reflection polarizer and an absorption polarizer 3 disposed on an optical path extending between the device and the filter. The reflection polarizer has a wavelength dependency which functions as a polarizer for the transmitting signal light, but does not function as a polarizer for the receiving signal light.

Abstract: A bidirectional optical module having a light-emitting device 1 for emitting transmitting signal light therefrom, an optical fiber 8 which the transmitting signal light emitted from the light-emitting device is made to enter, a light-receiving device 9 which receiving signal light made to emerge from the optical fiber is made to enter, and a wavelength splitting filter 4; the transmitting signal light emitted from the light-emitting device being sent forward through the optical fiber, and the receiving signal light being received through the optical fiber. The bidirectional optical module has an optical device (optical isolator) consisting essentially of a reflection type polarizer 6 bonded to an end face of the optical fiber, a Faraday rotator 5 disposed integrally on the reflection type polarizer and an absorption type polarizer 3 disposed on an optical path extending between the light-emitting device and the wavelength splitting filter.

Abstract: A Faraday rotator in which the isolation function based on a temperature rise is not deteriorated even when the Faraday rotator is used for a high output laser of not smaller than 1W output at a wavelength of not larger than 1.1 ?m includes sapphire crystals or rutile crystals bonded as radiation substrates to the incident side and outgoing side of a bismuth substituted type rare earth metal iron garnet crystal (RIG) film, the thickness of the RIG film being not smaller than 130 ?m and not larger than 200 ?m.

Abstract: A Faraday rotator is disclosed, in which the isolation function based on a temperature rise is not deteriorated even when the Faraday rotator is used for a high output laser of not smaller than 1W output at a wavelength of not larger than 1.1 ?m. Sapphire crystals or rutile crystals are bonded as radiation substrates to the incident side and outgoing side of a RIG film constituting the Faraday rotator, the thickness of the RIG film being set to not smaller than 130 ?m and not larger than 200 ?m.

Abstract: A non-destructive sugar content measuring apparatus having a plurality of trays on which vegetables and fruits are to be placed, a transport device for successively delivering the trays at appropriate intervals, and first, second and third measuring sections provided in the course of a transport path and at which laser beams having wavelengths &lgr;1, &lgr;2 and &lgr;3 are respectively made incident on each vegetable or fruit and the amount of light of each laser beam emergent from the vegetable or fruit is measured with a detector provided at each measuring section and the absorbance of each laser beam is determined from the amount of incident light made incident on the vegetable or fruit and the amount of detected light which has been measured with the detector, to measure the sugar content of the vegetables and fruits on the basis of each absorbance.

Abstract: A non-destructive sugar content measuring apparatus comprising a plurality of trays on which vegetables and fruits are to be placed, a transport means for successively delivering the trays at appropriate intervals, and first, second and third measuring sections provided in the course of a transport path and at which laser beams having wavelengths &lgr;1, &lgr;2 and &lgr;3 are respectively made incident on each vegetable or fruit and the amount of light of each laser beam emergent from the vegetable or fruit is measured with a detector provided at each measuring section and the absorbance of each laser beam is determined from the amount of incident light made incident on the vegetable or fruit and the amount of detected light which has been measured with the detector, to measure the sugar content of the vegetables and fruits on the basis of each absorbance.

Abstract: In a calibrator used for a non-destructive transmission optical measuring apparatus for quantitatively determining a specific component contained in a measuring object by making light incident on the measuring object at its light-incident area, detecting the light having entered, and having been transmitted through, the interior of the measuring object, at its light-emergent area set at a position different from the light-incident area, and measuring absorption of the light to quantitatively determine the specific component contained in the measuring object, the calibrator comprises a closed body having a light inlet and a light outlet, the interior of which is provided with a substrate having light absorption characteristics identical or similar to those of the specific component, and in which a light path length from the light inlet to the light outlet is so set as to be equal or substantially equal to an effective light path length of the light transmitted through the interior of the measuring object.

Abstract: A non-destructive taste characteristics measuring apparatus comprising trays and a measuring section provided in the course of a transport path and at which light is made incident on a vegetable or fruit to measure its taste characteristics, wherein the trays are each provided with at least two tray-side light passages one opening ends of which are so made as to come in contact with the vegetable or fruit and the other ends of which stand open outward at the bottom of the tray, and the measuring section has at least two measurement-side light passages one opening ends of which are positionally adjustable to the opening ends of the tray-side light passages at its part facing the bottom of said tray, and is provided with i) a means for making light incident on the vegetable or fruit through one of the measurement-side light passages and one of the tray-side light passages and ii) a detector which the light emergent from the vegetable or fruit enters through the other tray-side light passage and the other measur

Abstract: A non-destructive taste characteristics measuring apparatus comprising trays and a measuring section provided in the course of a transport path and at which light is made incident on a vegetable or fruit to measure its taste characteristics, wherein the trays are each provided with at least two tray-side light passages one opening ends of which are so made as to come in contact with the vegetable or fruit and the other ends of which stand open outward at the bottom of the tray, and the measuring section has at least two measurement-side light passages one opening ends of which are positionally adjustable to the opening ends of the tray-side light passages at its part facing the bottom of said tray, and is provided with i) a means for making light incident on the vegetable or fruit through one of the measurement-side light passages and one of the tray-side light passages and ii) a detector which the light emergent from the vegetable or fruit enters through the other tray-side light passage and the other measur

Abstract: A non-destructive sugar content measuring apparatus for determining the sugar content of a vegetable or fruit by measuring absorption of light in sugar when near infrared light is made incident on the vegetable or fruit; comprising at least one light source that emits light rays having three kinds of wavelengths within a wavelength range of from 860 nm to 960 nm, and a detector that detects the absorption of light.