Spectroscopic analysis

Abstract

An analyser and related methods for characterising a sample. The analyser includes an integrated laser for emitting electromagnetic radiation in at least one beam at a sample. The electromagnetic radiation can include at least two different wavelengths. A sample detector detects affected electromagnetic radiation resulting from the emitted electromagnetic radiation affected by the sample and provides output representing the detected affected radiation. The analyser also includes a processor for characterising the sample from the detector output representing the detected affected electromagnetic radiation.

1 . An analyser for characterising a sample comprising:
 an integrated laser for emitting electromagnetic radiation in at least one beam at a sample, the electromagnetic radiation comprising at least two different wavelengths,   a sample detector that detects affected electromagnetic radiation resulting from the emitted electromagnetic radiation affected by the sample and provides output representing the detected affected radiation, and   a processor for characterising the sample from the detector output representing the detected affected electromagnetic radiation.   
     
     
         2 . An analyser according to  claim 1  wherein the integrated laser comprises:
 a substrate, 
 two or more semi-conductor laser diodes (or other laser, lasing medium or similar) arranged on the substrate, and 
 a optical waveguide arranged on the substrate to combine outputs from the laser diodes into an output optical path. 
 
     
     
         3 . An analyser according to  claim 2  wherein the integrated laser further comprises:
 an optical modulator arranged on the substrate to modulate electromagnetic radiation in the output optical path. 
 
     
     
         4 . An analyser according to  claim 2  wherein the integrated laser further comprises a collimating lens that receives electromagnetic radiation from the output optical path and/or optical modulator and collimates it to emit the electromagnetic radiation at the sample. 
     
     
         5 . An analyser according to  claim 2  further comprising an optical fibre that is coupled to the output optical path and/or optical modulator to emit the electromagnetic radiation at the sample. 
     
     
         6 . An analyser according to  claim 2  wherein the optical waveguide comprises multiple paths and a combiner to combine the outputs from the laser diodes into the output optical path. 
     
     
         7 . An analyser according to  claim 2  wherein the integrated laser further comprises one or more monitor diodes arranged to detect one or more of the laser diode outputs to measure the output power of the laser diodes. 
     
     
         8 . An analyser according to  claim 2  wherein the integrated laser further comprises one or more monitor diodes arrange to detect the electromagnetic radiation on the output optical path, optical fibre and/or optical modulator to measure the output power of the laser diodes. 
     
     
         9 . An analyser according to  claim 2  wherein the integrated laser further comprises an integrated thermo-electric cooling/heating device to control the temperature of the integrated laser. 
     
     
         10 . An analyser according to  claim 9  wherein the integrated thermo-electric cooling/heating device is a Peltier device and/or thermistor. 
     
     
         11 . An analyser according to  claim 1  wherein the sample comprises one or more of (in solid, liquid, powdered, gas or any other form):
 a drug (legitimate or illegal), blood, milk, glucose, foodstuffs, powder samples, 
 and characterisation comprises one or more of: 
 verification, identification, constituent analysis, concentration, volume. 
 
     
     
         12 . An analyser according to  claim 11  wherein the wavelengths used are as follows:
 drug (1100 nm to 2000 nm), blood (visible and near infrared), milk (visible and near infrared), glucose (near infrared and greater than 2000 nm), pharmaceutical drugs in table or powdered form (visible and near infrared). 
 
     
     
         13 . A method for characterising a sample comprising:
 providing an integrated laser for emitting electromagnetic radiation in at least one beam at a sample, the electromagnetic radiation comprising at least two different wavelengths,   providing at least one detector for detecting affected electromagnetic radiation resulting from the emitted electromagnetic radiation affected by the sample and provides output representing the detected affected radiation, and   providing a processor for characterising the sample from the detector output representing the detected affected electromagnetic radiation.   
     
     
         14 . A method according to  claim 13  wherein the integrated laser is as defined in any one of  claims 1  to  11 . 
     
     
         15 . A method according to  claim 13  wherein each laser diode can be switched on, off or modulated by a suitable waveform, such as sinusoid, squarewave, sawtooth or the like.