Multi user UV-VIS/NIR Array Spectrophotometer using a Fiber Optic Probe/Sphere and Photonic Switches

Background of the invention:

The Spectrophotometers in any analytical laboratory are restricted to one user at a time. No one has conceived of a process of multiple users using the same spectrophotometer at same time for different analysis.

Prior Art: The fiber optic channel selecting apparatus (Patent no. US6496618 B1) and photonic switches (patent no. US5103333) and Fiber Optic Channel Selecting Device (Patent no. US 6950568 B2) are already known.

Fig.3 shows the first embodiment of a photonic switch with a time-slot interchanger (numeral I) using N reentrant fiber-loop memories (numeral II), as described by Thompson. The 1 x N optical switch (numeral III) and the N x 1 Optical Switch (numeral IV) are series of N interconnected 1 x 2 optical switches (numeral V). Each fiber loop memory includes a 2 x 2 optical switch (numeral Vl) that is implemented by lithium niobate directional couplers. A clock (numeral VII), controller (numeral VIII) and drivers (numeral IX) complete the system.

Fig.4 illustrates the use of a 2 x 2 (numeral 1) cascade - structured integrated optical switch (numeral II) in a fiber loop delay line (numeral IV) memory (numeral III) of the type shown Fig. 3. Switch Il can be used to replace some or all of the conventional directional coupler switches Vl in the fiber loop memory (numeral II) of fig.2 to significantly reduce any cross talk or the non- addressed spurious light.

Over all design:

Spectrophotometer Specifications:

Multi User UV-VIS-NIR Spectrophotometer.

Spectrophotometer type Bench top:

Spectral range: 190-1100-3200 nm.

i

Wavelength Interval: 0.1 nm.

Source: Xenon Flash Lamp/Deuterium/Tungsten Halogen

Measurement Mode: Absorbance and % Transmission, %Reflectance.

Measurement principle: Double Beam/Single Beam.

Photometric Range: 0-100% or -3 to +3 AU.

Photometric Accuracy: 0.01% Transmission or 0.001 AU.

Calibration: Solvents, BaSO ₄

Sphere Geometry: This can be D/8, D/0, 45/0, 0/45, D (hemisphere)/8, D(hemisphere)/0 Invention patent applies to all the above geometries and 180° for Transmission.

Detector: Photodiode array / CCD

Fiber optic Probe: A two way fiber optic to transmit the incident light pulse on to the sample and also returns the transmitted or reflected signal from the sample to the instrument. Photonic Switch: n x n (where n is > 2).

Summary of the invention

The present invention discloses a multi user environment for a single spectrophotometer using fiber optic probes/spheres and photonic switches.

The spectrophotometer and the fiber optic probe/sphere act as server/client architecture where the spectrophotometer is the server and the fiber optic probe/sphere is the client. The client set up is at the user end. The spectrophotometer is connected to a server computer while each user has client systems. Through the client computer each user sends the input data to the spectrophotometer through the server. The relevant wavelength light for transmission or absorbance or reflectance depending on the user's requirement passes through the different input channels of the photonic switch and reaches the sample holder through the fiber optic probe or the sphere through the output channel of the photonic switch. The signal from the photonic switch comes back to the output channel of the photonic switch through the two way fiber optic probe and falls on the detector of the spectrophotometer and the data is transferred to client computer through the server ^' computer.

In the multi user environment, the switch over time from user to user in the photonic switch, in the spectrophotometer, transfer of data and usage of two fiber optic probe depends on the specifications of photonic switch chosen, This architecture finds application in any analytical lab conditions, where a spectrophotometer has to be used by multiple number of lab personnel. The spectrophotometer is an array based or CCD based, in the working range of UV/VIS/NIR.

Brief Description of Drawings

Fig.1 is a ^~ block diagram showing the configuration of the multi user architecture with the instrument.

Fig.2 is a flow chart showing the different operations incorporated in the architecture.

Fig.3 is a diagram of a prior art photonic switch using a re-entrant fiber loops.

Fig.4 is a schematic diagram of a prior art of an optical re-entrant memory using a two-stage cascade structured integrated optical 2 x 2 switch.

Description of the invention:

Fig.1 is a block diagram showing the configuration of multi user architecture with the instrument, according to an embodiment of the present invention is applicable. Referring to Fig.1, numeral V, the spectrophotometer (which is a diode array based or CCD based), acts as a server, which takes the inputs from the client PCs at the user end (U 1 to U4) through the server PC (numeral Vl) connected directly to the spectrophotometer. Numeral I ₁ the light source (UV/VIS/NIR) transfer light to the respective fiber optic probes (numeral IIIA)/spheres (numeral IHB) at the respective users end (U 1 to U4) through the different channels of the photonic switch (numeral II). The light through the fiber optic probe falls on the sample holder and the light transmitted or reflected signal from the different samples at the respective users end depending on their respective applications passes through the respective fiber optic probes. They reach their respective channel positions in the photonic switch (numeral IV) and fall on the diode array of the spectrophotometer (numeral V). The output data from the detector of the spectrophotometer from respective channels reaches the client computers (U 1 to U4) of the respective users through the server computer (numeral Vl) attached to the spectrophotometer (numeral V).

Fig.2 is a flowchart showing an example of the multi user environment using a spectrophotometer, photonic switch and fiber optic probe/ sphere system according to an embodiment of the present invention, Numerals, 1 to 6 represent the processing steps for prompting the incidence of the wavelengths of light on the sample from independent users (n no.) When started the system shown in Fig.1 executes an initialization process and transfers the light onto different samples for the different users independently and simultaneously.

Numerals, 7 to 10 represent the processing steps for capturing the transmitted or reflected light based on each user's application. When started the system shown in Fig.1 captures the signals from different users simultaneously and independently and transfers to the spectrophotometer diode array detector or CCD through the photonic switch and further to the respective client computers of the users through the spectrophotometer server computer for further processing.

The architecture in the patent, works on the principle of computers client server architecture. The Spectrophotometer is like the server and would facilitate any number (say n) of users at the same time for different analyses of their requirement through network switches. This is facilitated through the usage of a Fiber Optic Probe/Sphere and Photonic Switches. At the desk of each user a Fiber Optic Probe or Sphere based on the application is provided as a client. Then n number of Fiber Optic Probes/Spheres would be connected through the photonic switch to the Spectrophotometer, which would facilitate the user to choose his parameters of analysis, through simultaneous wavelength sensing with appropriate software installed in the PC connected to the Spectrophotometer through regular computer network.

The spectrophotometer and the fiber optic probe/sphere act as server/client architecture where the spectrophotometer is the server and the fiber optic probe/sphere is the client. The client set up is at the user end. The spectrophotometer is connected to a server computer while each user has client systems. Through the client computer each user sends the input data to the ^• spectrophotometer through the server. The relevant wavelength light for transmission or absorbance or reflectance depending on the user's requirement passes through the different input channels of the photonic switch and reaches the sample holder through the fiber optic probe or the sphere through the output channel of the photonic switch. The signal from the photonic switch comes back to the output channel of the photonic switch through the two way fiber optic probe and falls on the detector of the spectrophotometer and the data is transferred to client computer through the server computer.

In the multi user environment, the switch over time from user to user in the photonic switch, in the spectrophotometer, transfer of data and usage of two fiber optic probe depends on the specifications of photonic switch chosen. This architecture finds application in any analytical lab conditions, where a spectrophotometer has to be used by multiple number of lab personnel. The spectrophotometer is an array based or CCD based, in the working range of UV/VIS/NIR.

Over all design:

Spectrophotometer Specifications:

Multi User UV-VIS-NIR Spectrophotometer.

Spectrophotometer type Bench top:

Spectral range: 190-1100-3200 nm.

Wavelength Interval: 0.1 nm.

Source: Xenon Flash Lamp/Deuterium/Tungsten Halogen

Measurement Mode: Absorbance and % Transmission, %Reflectance.

Measurement principle: Double Beam/Single Beam.

Photometric Range: 0-100% or -3 to +3 AU.

Photometric Accuracy: 0.01% Transmission or 0.001 AU.

Calibration: Solvents, BaSO ₄

Sphere Geometry: This can be D/8, D/0, 45/0, 0/45, D (hemisphere)/8, D(hemisphere)/0 Invention patent applies to all the above geometries and 180° for Transmission.

Detector: Photodiode array / CCD

Fiber optic Probe: A two way fiber optic to transmit the incident light pulse on to the sample and also returns the transmitted or reflected signal from the sample to the instrument. Photonic Switch: n x n (where n is > 2).