The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula:
in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula:
eff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2. The first grating region is a first-order grating region, and the second grating region is a second-order grating region, so as to form a hybrid grating structure in the grating layer. The surface emitting laser emits laser light perpendicularly from a light-emitting surface defined by the second grating region.
H01S 5/11 - Structure ou forme du résonateur optique comprenant une structure de bande photonique interdite
H01S 5/12 - Structure ou forme du résonateur optique le résonateur ayant une structure périodique, p. ex. dans des lasers à rétroaction répartie [lasers DFB]
H01S 5/183 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités verticales, p. ex. lasers à émission de surface à cavité verticale [VCSEL]
H01S 5/185 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités horizontales, p. ex. lasers à émission de surface à cavité horizontale [HCSEL]
H01S 5/32 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures
2.
Surface emitting laser with hybrid grating structure
The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula:
in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula:
eff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2. The first grating region is a first-order grating region, and the second grating region is a second-order grating region, so as to form a hybrid grating structure in the grating layer. The surface emitting laser emits laser light perpendicularly from a light-emitting surface defined by the second grating region.
H01S 5/11 - Structure ou forme du résonateur optique comprenant une structure de bande photonique interdite
H01S 5/12 - Structure ou forme du résonateur optique le résonateur ayant une structure périodique, p. ex. dans des lasers à rétroaction répartie [lasers DFB]
H01S 5/183 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités verticales, p. ex. lasers à émission de surface à cavité verticale [VCSEL]
H01S 5/185 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités horizontales, p. ex. lasers à émission de surface à cavité horizontale [HCSEL]
H01S 5/32 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures
3.
Surface emitting laser with hybrid grating structure
The grating layer of a surface emitting laser is divided into a first grating region and a second grating region along a horizontal direction. The second grating region is located at a middle area of the grating layer, while the first grating region is located in an outer peripheral area of the grating layer. Each of the first and second grating regions comprises a plurality of micro-grating structures. The grating period of the micro-grating structures in the first grating region is in accordance with the following mathematical formula:
in addition, the grating period of the micro-grating structures in the second grating region is in accordance with the following mathematical formula:
eff is the equivalent refractive index of semiconductor waveguide, m=1, and o=2. The first grating region is a first-order grating region, and the second grating region is a second-order grating region, so as to form a hybrid grating structure in the grating layer. The surface emitting laser emits laser light perpendicularly from a light-emitting surface defined by the second grating region.
H01S 5/11 - Structure ou forme du résonateur optique comprenant une structure de bande photonique interdite
H01S 5/12 - Structure ou forme du résonateur optique le résonateur ayant une structure périodique, p. ex. dans des lasers à rétroaction répartie [lasers DFB]
H01S 5/183 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités verticales, p. ex. lasers à émission de surface à cavité verticale [VCSEL]
H01S 5/32 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures
H01S 5/185 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités horizontales, p. ex. lasers à émission de surface à cavité horizontale [HCSEL]
4.
Structure of vertical cavity surface emitting laser
A structure of Vertical Cavity Surface-Emitting Laser (VCSEL) comprises an ion-implanted region with gas-furnace configuration arranged in the second mirror layer around a laser light output window, in order to retain several conductive passages between the inner and outer rims of the ion-implanted region, so as to let the aperture of the inner rim of the metal layer (that is, the aperture of the output window) be expanded without loss of resistance. Not only the shading effect can be removed, the spectrum width suppression function can be preserved, but also various photoelectric characteristics such as transmission eye diagram and photoelectric curve linearity can be improved, in addition, high-speed transmission characteristics can also be optimized.
H01S 5/183 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités verticales, p. ex. lasers à émission de surface à cavité verticale [VCSEL]
H01S 5/323 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures dans des composés AIIIBV, p. ex. laser AlGaAs
H01S 5/187 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités horizontales, p. ex. lasers à émission de surface à cavité horizontale [HCSEL] à réflexion de Bragg
H01S 5/20 - Structure ou forme du corps semi-conducteur pour guider l'onde optique
5.
Structure and fabricating method of distributed feedback laser
A structure of distributed feedback (DFB) laser includes a grating layer having a phase-shift grating structure and a gratingless area. In addition, both side-surfaces of the DFB laser are coated with anti-reflection coating to improve SMSR and to obtain good slope efficiency (SE). The grating layer is divided by the phase-shift grating structure in a horizontal direction into a first grating area and a second grating area adjacent to a laser-out surface of the DFB laser. The phase-shift grating structure provides a phase-difference distance, such that a shift of phase exists between the micro-grating structures located within the first grating area and the other micro-grating structures located within the second grating area. The gratingless area located within the second grating area contains no micro-grating structure, and moreover, the gratingless area will not change the phase of the micro-grating structures located within the second grating area.
H01S 5/12 - Structure ou forme du résonateur optique le résonateur ayant une structure périodique, p. ex. dans des lasers à rétroaction répartie [lasers DFB]
H01S 5/026 - Composants intégrés monolithiques, p. ex. guides d'ondes, photodétecteurs de surveillance ou dispositifs d'attaque
H01S 5/02 - Détails ou composants structurels non essentiels au fonctionnement laser
True Light Corporation (Taïwan, Province de Chine)
Inventeur(s)
Yeh, Tzu-Ching
Wu, Yu-Fu
Chen, Cheng-Ta
Abrégé
A packaging assembly for a high-speed vertical-cavity surface-emitting laser (VCSEL) mainly applies a lens assembly consisted of several prisms to split a laser beam emitted by a VCSEL element so as to guide a small portion of the laser beam back to a monitor photodiode (MPD) and the rest of the laser beam to travel away along an optical axis. Such a spectacular design of the lens assembly can not only relieve the VCSEL element from a position right under the optical axis, but can also reduce signal loss by shorting a length of a bonding wire for a corresponding pin through disposing the VCSEL element further close to the corresponding pin. Thereupon, a defect of lights reflected from a lens or a translucent plate on a cap can be substantially improved.
H01S 5/183 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités verticales, p. ex. lasers à émission de surface à cavité verticale [VCSEL]
H01S 5/0683 - Stabilisation des paramètres de sortie du laser en surveillant les paramètres optiques de sortie
7.
Edge-emitting laser having small vertical emitting angle
An edge-emitting laser having a small vertical emitting angle includes an upper cladding layer, a lower cladding layer and an active region layer sandwiched between the upper and lower cladding layers. By embedding a passive waveguide layer within the lower cladding to layer, an extended lower cladding layer is formed between the passive waveguide layer and the active region layer. In addition, the refractive index (referred as n-value) of the passive waveguide layer is larger than the n-value of the extended lower cladding layer. The passive waveguide layer with a larger n-value would guide the light field to extend downward. The extended lower cladding layer can separate the passive waveguide layer and the active region layer and thus expand the near-field distribution of laser light field in the resonant cavity, so as to obtain a smaller vertical emitting angle in the far-field laser light field.
H01S 5/20 - Structure ou forme du corps semi-conducteur pour guider l'onde optique
H01S 5/32 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures
H01S 5/323 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures dans des composés AIIIBV, p. ex. laser AlGaAs
H01S 5/343 - Structure ou forme de la région activeMatériaux pour la région active comprenant des structures à puits quantiques ou à superréseaux, p. ex. lasers à puits quantique unique [SQW], lasers à plusieurs puits quantiques [MQW] ou lasers à hétérostructure de confinement séparée ayant un indice progressif [GRINSCH] dans des composés AIIIBV, p. ex. laser AlGaAs
8.
Structure of VCSEL and method for manufacturing the same
A vertical-cavity surface-emitting Laser (VCSEL) has a three-trench structure. By forming a first trench within a mesa around the periphery of an output window of the VCSEL, the overall capacitance is decreased and the time used in the oxidation process for an oxidation layer is shortened. By forming a second trench and a third trench on the periphery of the mesa in a step-like concave manner, the mesa becomes a step-like structure having double mesa-layers. Such that, a larger heat-radiating area can be obtained for decreasing thermal effects, while the metal-gap defects of the metal layer can also be avoided. The implant layer is formed around the periphery of the output window for controlling the optical mode and confining the current path. In addition, an output layer is formed on the output window for controlling the output light.
H01S 5/183 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités verticales, p. ex. lasers à émission de surface à cavité verticale [VCSEL]
H01S 5/22 - Structure ou forme du corps semi-conducteur pour guider l'onde optique ayant une structure à nervures ou à bandes
H01S 5/187 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités horizontales, p. ex. lasers à émission de surface à cavité horizontale [HCSEL] à réflexion de Bragg
9.
High-speed multi-channel optical transmitter module and method for fabricating the same
A high-speed multi-channel optical transmitter module includes a plurality of laser-diode (LD) components, a plurality of photo-diode (PD) components, an MT ferrule, and a waveguide component. These components are firstly packaged as sub-modules individually, and then these sub-modules are packaged to form the high-speed multi-channel optical transmitter module. Therefore, the amount of individual components contained in the module is decreased, the complexity of structure is simplified, the precision of positioning is increased, such that the time and labors required in the assembling and packaging processes can be decreased, and the defect-free rate of products can be increased.
An edge-emitting laser having a small vertical emitting angle includes an upper cladding layer, a lower cladding layer and an active region layer sandwiched between the upper and lower cladding layers. By embedding a passive waveguide layer within the lower cladding layer, an extended lower cladding layer is formed between the passive waveguide layer and the active region layer. In addition, the refractive index (referred as n-value) of the passive waveguide layer is larger than the n-value of the extended lower cladding layer. The passive waveguide layer with a larger n-value would guide the light field to extend downward. The extended lower cladding layer can separate the passive waveguide layer and the active region layer and thus expand the near-field distribution of laser light field in the resonant cavity, so as to obtain a smaller vertical emitting angle in the far-field laser light field.
H01S 5/20 - Structure ou forme du corps semi-conducteur pour guider l'onde optique
H01S 5/32 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures
H01S 5/323 - Structure ou forme de la région activeMatériaux pour la région active comprenant des jonctions PN, p. ex. hétérostructures ou doubles hétérostructures dans des composés AIIIBV, p. ex. laser AlGaAs
H01S 5/343 - Structure ou forme de la région activeMatériaux pour la région active comprenant des structures à puits quantiques ou à superréseaux, p. ex. lasers à puits quantique unique [SQW], lasers à plusieurs puits quantiques [MQW] ou lasers à hétérostructure de confinement séparée ayant un indice progressif [GRINSCH] dans des composés AIIIBV, p. ex. laser AlGaAs
11.
Structure of VCSEL and method for manufacturing the same
A vertical-cavity surface-emitting Laser (VCSEL) has a three-trench structure. By forming a first trench within a mesa around the periphery of an output window of the VCSEL, the overall capacitance is decreased and the time used in the oxidation process for an oxidation layer is shortened. By forming a second trench and a third trench on the periphery of the mesa in a step-like concave manner, the mesa becomes a step-like structure having double mesa-layers. Such that, a larger heat-radiating area can be obtained for decreasing thermal effects, while the metal-gap defects of the metal layer can also be avoided. The implant layer is formed around the periphery of the output window for controlling the optical mode and confining the current path. In addition, an output layer is formed on the output window for controlling the output light.
H01S 5/183 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités verticales, p. ex. lasers à émission de surface à cavité verticale [VCSEL]
H01S 5/187 - Lasers à émission de surface [lasers SE], p. ex. comportant à la fois des cavités horizontales et verticales comportant uniquement des cavités horizontales, p. ex. lasers à émission de surface à cavité horizontale [HCSEL] à réflexion de Bragg
H01S 5/22 - Structure ou forme du corps semi-conducteur pour guider l'onde optique ayant une structure à nervures ou à bandes
A thin optical imaging module of a biometric apparatus includes a first glass substrate, a first optical prism film, a second optical prism film, and an image sensor. The first glass substrate further includes a fingerprint imaging area, a vein imaging area, a contact surface, a reflective interface, and an attaching surface. The first optical prism film adhered to the attaching surface is located under the fingerprint imaging area. The second optical prism film is adhered to a position under the first optical prism film. The image sensor disposed in correspondence to the first glass substrate is located under the attaching surface.
G06K 9/00 - Méthodes ou dispositions pour la lecture ou la reconnaissance de caractères imprimés ou écrits ou pour la reconnaissance de formes, p.ex. d'empreintes digitales
A biometric authentication device uses IR-VCSELs as light sources for performing biometric authentication by providing clear images. A light guide module is introduced to minimize the size of the device. Moreover, the biometric authentication device uses a single image sensing module to gather a vein image and a fingerprint image into the same detection signal which is then analyzed and compared with the pre-stored vein feature data and fingerprint feature data.
G06K 9/00 - Méthodes ou dispositions pour la lecture ou la reconnaissance de caractères imprimés ou écrits ou pour la reconnaissance de formes, p.ex. d'empreintes digitales
An alignment jig for an optical lens array is furnished on an optical alignment apparatus. The alignment machine is for performing active optical alignment operations of a sensor chip located on a circuit board and a lens socket plugged with a fiber plug. The alignment jig includes a support arm, a pick-up mechanism and a pushing mechanism. The support arm is fixed to the optical alignment apparatus for supporting the alignment jig. The pick-up mechanism is furnished on the support arm for picking-up and holding the lens socket in a detachable manner at a predetermined position corresponding to the sensor chip. The pushing mechanism holds the plugging status when the fiber plug is plugged into the lens socket and provides a pushing force, such that the fiber plug has a tendency to be pushed toward and engage the lens socket tightly.
A chip array structure for laser diodes, formed on an active surface of a semiconductor chip produced from a semiconductor process includes a plurality of light-emitting elements in an array arrangement, at least one insulation wall, at least two wire bond areas and a plurality of connection electrodes. The insulation wall separates the light-emitting elements into at least two light-emitting districts. The wire bond areas are positioned respective to the corresponding light-emitting districts. The connection electrodes electrically couple the wire bond areas with the corresponding light-emitting districts. The wire bond areas have independent electrodes, and the light-emitting districts are electrically isolated by the insulation wall.
H01L 27/15 - Dispositifs consistant en une pluralité de composants semi-conducteurs ou d'autres composants à l'état solide formés dans ou sur un substrat commun comprenant des composants semi-conducteurs avec au moins une barrière de potentiel ou une barrière de surface, spécialement adaptés pour l'émission de lumière
A biometric authentication device uses IR-VCSELs as light sources for performing a better biometric authentication by providing clearer images. A light guide module is introduced to minimize the size of the device. Moreover, the biometric authentication device uses a single image sensing module to gather the vein image and the fingerprint image into the same detection signal which is then analyzed and compared with the pre-stored vein feature data and fingerprint feature data. Therefore, the biometric authentication device can achieve an approach in lowering hardware costs, simplifying circuit designs and providing an outstanding performance.
G06K 9/00 - Méthodes ou dispositions pour la lecture ou la reconnaissance de caractères imprimés ou écrits ou pour la reconnaissance de formes, p.ex. d'empreintes digitales
17.
Vertical cavity surface emitting laser and manufacturing method thereof
True Light Corporation (Taïwan, Province de Chine)
Inventeur(s)
Chen, Po-Han
Wu, Cheng-Ju
Pan, Jin-Shan
Abrégé
The present invention discloses a manufacturing method of vertical cavity surface emitting laser. The method includes following steps: providing a substrate; forming an epitaxial layer stack including an aluminum-rich layer; forming an ion-doping mask including a ring-shaped opening; doping ions in the epitaxial layer stack through the ring-shaped opening and forming a ring-shaped ion-doped region over the aluminum-rich layer; forming an etching mask on the ion-doping mask for covering the ring-shaped opening of the ion-doping mask; etching the epitaxial layer stack through the etching mask and ion-doping mask for forming an island platform; oxidizing the aluminum-rich layer for forming a ring-shaped oxidized region. In addition, the present invention also discloses a vertical cavity surface emitting laser manufactured by the above mentioned method.
H01L 21/302 - Traitement des corps semi-conducteurs en utilisant des procédés ou des appareils non couverts par les groupes pour changer leurs caractéristiques physiques de surface ou leur forme, p. ex. gravure, polissage, découpage
18.
Packaging device for matrix-arrayed semiconductor light-emitting elements of high power and high directivity
A packaging device for matrix-arrayed semiconductor light-emitting elements of high power and high directivity comprises a metal base, an array chip and a plurality of metal wires. The metal base is of highly heat conductive copper or aluminum, and a first electrode area and at least one second electrode area which are electrically isolated are disposed on the metal base. The array chip is disposed on the first electrode area, on which multiple matrix-arranged semiconductor light-emitting elements and at least one wire bond pad adjacent to the light-emitting elements are disposed. The light-emitting element is a VCSEL element, an HCSEL element or an RCLED element. The metal wires are connected between the wire bond pad and the second electrode area to transmit power signals. Between the bottom surface and the first electrode area is disposed a conductive adhesive to bond and facilitate electrical connection between the two.
A packaging device for matrix-arrayed semiconductor light-emitting elements of high power and high directivity comprises a metal base, an array chip and a plurality of metal wires. The metal base is of highly heat conductive copper or aluminum, and a first electrode area and at least one second electrode area which are electrically isolated are disposed on the metal base. The array chip is disposed on the first electrode area, on which multiple matrix-arranged semiconductor light-emitting elements and at least one wire bond pad adjacent to the light-emitting elements are disposed. The light-emitting element is a VCSEL element, an HCSEL element or an RCLED element. The metal wires are connected between the wire bond pad and the second electrode area to transmit power signals. Between the bottom surface and the first electrode area is disposed a conductive adhesive to bond and facilitate electrical connection between the two.
True Light Corporation (Taïwan, Province de Chine)
Inventeur(s)
Chen, Chih-Cheng
Pan, Jin-Shan
Abrégé
A submount is used for disposing an illuminant element or a light-receiving element having an optical axis. The submount is disposed at a plane and has a main body. The main body includes a first surface and a second surface. The first surface is approximately parallel to the plane and far away from the plane. The second surface is approximately parallel to the plane and adjacent to the plane. A disposing part of the first surface is tilted with respect to the second surface at a predetermined angle. The illuminant element or the light-receiving element is disposed on the disposing part. The optical axis of the illuminant element or the light-receiving element is tiled with respect to a normal of the second surface at the predetermined angle.
True Light Corporation (Taïwan, Province de Chine)
Inventeur(s)
Chen, Chih-Cheng
Pan, Jin-Shan
Abrégé
A light source unit is disclosed for arranging on a plane and emitting a light beam oblique to the plane. The light source unit includes an illuminant element and a transparent encapsulator. The illuminant element has an upper surface and a lower surface both parallel to the plane. The transparent encapsulator physically contacts with the illuminant element and at least covers the upper surface of the illuminant element. The transparent encapsulator has an oblique surface above the upper surface and oblique to the upper surface. In addition, an optical inputting module having the light source unit mentioned above is disclosed.
A packaging device for matrix-arrayed semiconductor light-emitting elements of high power and high directivity comprises a metal base, an array chip and a plurality of metal wires. The metal base is of highly heat conductive copper or aluminum, and a first electrode area and at least one second electrode area which are electrically isolated are disposed on the metal base. The array chip is disposed on the first electrode area, on which multiple matrix-arranged semiconductor light-emitting elements and at least one wire bond pad adjacent to the light-emitting elements are disposed. The light-emitting element is a VCSEL element, an HCSEL element or an RCLED element. The metal wires are connected between the wire bond pad and the second electrode area to transmit power signals. Between the bottom surface and the first electrode area is disposed a conductive adhesive to bond and facilitate electrical connection between the two.
The present invention discloses a method for fabricating a heat-resistant, humidity-resistant oxide-confined vertical-cavity surface-emitting laser (VCSEL) by slowing down the oxidizing rate during a VCSEL oxidation process to thereby reduce stress concentration of an oxidation layer and by preventing moisture invasion using a passivation layer disposed on a laser window. The VCSEL device thus fabricated is heat-resistant, humidity-resistant, and highly reliable. In a preferred embodiment, the oxidation process takes place at an oxidizing rate of less than 0.4 μm/min, and the passivation layer is a SiON passivation layer.
H01L 21/00 - Procédés ou appareils spécialement adaptés à la fabrication ou au traitement de dispositifs à semi-conducteurs ou de dispositifs à l'état solide, ou bien de leurs parties constitutives
H01L 33/00 - DISPOSITIFS À SEMI-CONDUCTEURS NON COUVERTS PAR LA CLASSE - Détails
H01S 3/04 - Dispositions pour la gestion thermique
A multiple function thin-film resistor-capacitor array is used for an optical fiber receiving module. A dielectric thin film with desired pattern and thickness is form on surface of a silicon substrate by semiconductor manufacture process. Resistors of different resistances and capacitors of different capacitances or the combination thereof, and circuit connection therebetween can be provided by controlling the thickness and shape of thin film. The thickness of the thin-film resistor-capacitor array is adjusted by grinding to provide a substrate of a photodiode. The photodiode can be die bonded to the resistor-capacitor array with desired optical position.
H01L 21/00 - Procédés ou appareils spécialement adaptés à la fabrication ou au traitement de dispositifs à semi-conducteurs ou de dispositifs à l'état solide, ou bien de leurs parties constitutives
25.
Bi-directional optical signal transmitting and receiving device
A bi-directional transmitting and receiving device for the connection of optical fiber is mainly to apply one side of a T shape shell to connect an optical fiber, while another side of the shell in line with the optical fiber is arranged an optical transmitter, with an optical receiver being arranged at the third side of the shell, wherein the optical transmitter is a packaging structure of Transistor Outline can (TO-can) having a cup shape lid, of which underside is inclined 45 degrees to transmitted light beam, and wherein a hollow window in the underside of the lid is arranged a light splitting filter, which is just positioned at the beam path of the optical receiver.
brevets