Apparatus, a Handheld Electronic Device, and a Method for Carrying Out Raman Spectroscopy

Abstract

An apparatus, a handheld electronic device and a method for carrying out Raman Spectroscopy are disclosed. In an embodiment an apparatus includes at least one optoelectronic laser configured to provide excitation radiation to a sample, the excitation radiation being generated by an electric current flowing through the at least one optoelectronic laser during operation of the apparatus and a transistor configured to modulate the electric current flowing through the at least one optoelectronic laser, to thereby switch on and off generation of the excitation radiation.

What is claimed is: 
     
         1 . An apparatus for carrying out Raman spectroscopy on a sample, the apparatus comprising:
 at least one optoelectronic laser configured to provide excitation radiation to the sample, the excitation radiation being generated by an electric current flowing through the at least one optoelectronic laser during operation of the apparatus; and   a transistor configured to modulate the electric current flowing through the at least one optoelectronic laser, to thereby switch on and off generation of the excitation radiation.   
     
     
         2 . The apparatus of  claim 1 , wherein the at least one optoelectronic laser is a DFB laser diode or DBR laser diode. 
     
     
         3 . The apparatus of  claim 1 , wherein the transistor comprises an electric contact and the optoelectronic laser comprises an electric contact, and wherein the electric contact of the transistor is directly coupled electrically to the electric contact of the optoelectronic laser. 
     
     
         4 . The apparatus of  claim 1 , wherein the transistor is a GaN FET configured to operate the at least one optoelectronic laser such as to generate pulsed excitation radiation. 
     
     
         5 . The apparatus of  claim 1 , wherein the at least one optoelectronic laser is configured to generate pulses of excitation light, wherein each pulse has a time duration of less than 200 ps. 
     
     
         6 . The apparatus of  claim 1 , further comprising a temperature sensor configured to monitor a temperature of the at least one optoelectronic laser. 
     
     
         7 . The apparatus of  claim 1 , further comprising a Bragg grating. 
     
     
         8 . The apparatus of  claim 1 , further comprising a spectrometer configured to analyse Raman light scattered from the sample in response to exposing the sample to the excitation radiation, wherein Raman light comprises one or more spectral components, and wherein the spectrometer comprises diffraction element configured to split the Raman light into its spectral components. 
     
     
         9 . The apparatus of  claim 8 ,
 wherein the diffraction element comprises at least one of the following:   a diffraction grating,   a photonic crystal, or   a plasmonic Fabry Perot filter.   
     
     
         10 . The apparatus of  claim 1 , further comprising a driver for the transistor, wherein the driver is configured to provide a control signal for controlling operation of the transistor. 
     
     
         11 . The apparatus of  claim 10 , further comprising a shutter between a spectrometer and a detector configured to detect spectral lines in a Raman signal, wherein the spectral lines are spatially split by the spectrometer from the Raman signal, and wherein the shutter is operated based on the control signal. 
     
     
         12 . The apparatus of  claim 10 , further comprising a scanning mirror between a spectrometer and a detector for detecting spectral lines in a Raman signal, wherein the spectral lines are spatially split by the spectrometer from the Raman signal, and wherein the scanning mirror is operated based on the control signal. 
     
     
         13 . A handheld electronic device comprising:
 a housing; and   an apparatus with at least one optoelectronic laser configured to provide excitation radiation to a sample, the excitation radiation being generated by an electric current flowing through the at least one optoelectronic laser during operation of the apparatus,   wherein the apparatus further comprises a transistor configured to modulate the electric current flowing through the at least one optoelectronic laser, to thereby switch on and off generation of the excitation radiation, and   wherein the apparatus is arranged in the housing of the handheld electronic device.   
     
     
         14 . The handheld electronic device of  claim 13 , wherein the handheld electronic device is a smartphone or a tablet. 
     
     
         15 . A method of carrying out Raman spectroscopy on a sample, the method comprising:
 providing, by at least one optoelectronic laser of an apparatus, excitation radiation to the sample, the excitation radiation being generated by an electric current flowing through the at least one optoelectronic laser during operation of the apparatus, wherein the apparatus further comprises a transistor for modulating the electric current flowing through the at least one optoelectronic laser, to thereby switch on and off generation of the excitation radiation; and   operating the transistor such as to cause the at least one optoelectronic laser to generate pulses of excitation radiation.   
     
     
         16 . An apparatus for carrying out Raman spectroscopy on a sample, the apparatus comprising:
 a GaN FET; and   at least one DFB or DBR laser,   wherein the GaN FET is configured to directly modulate the DFB or DBR laser for generating at least one laser pulse which fast enough to capture Raman scatter prior to fluorescence.   
     
     
         17 . The apparatus of  claim 16 , further comprising tandem slits and/or MEMS mirrors configured to image while a laser modulation signal is used to as a frame sync.