A hand held Raman spectroscopic instrument for pathogen detection, comprising: a housing having a handle portion, a head portion and an end effector; a Raman spectroscopic probe encased in the housing and including: a laser disposed in the handle portion and operable to emit a coherent light beam; a laser line filter operable to transmit the light beam along an optical path and suppress ambient light; a beam splitter disposed in the head portion and operable to reflect the light beam from the laser line filter through an aperture formed in the end effector toward onto a sample to produce a Raman-shifted sample signal; a collector to collect the sample signal and transmit the sample signal through the beam splitter; a beam expander to collimate the sample signal from the beam splitter and generate an expanded diameter sample signal; an ultra-high resolution, narrow range, spatially graded filter to filter the expanded diameter sample signal in at least one narrow spectral band based on a predetermined set of discrete spectral bands for a target pathogen, wherein the filter is a band gap filter comprising graded indium aluminum nitride alloy; and an imager for converting the expanded diameter sample signal to image data representative of the Raman-shifted sample signal; and an electronics assembly including: a micro-controller encased within the housing for controlling the Raman spectroscopic probe, reading the image data from the imager, and analyzing the image data at the discrete spectral bands to detect the presence of the target pathogen, comparing the image data with a baseline Raman spectrum and communicating a test result based on the analysis and comparison; and a power source operably coupled to the micro-controller and the Raman spectroscopic probe. a housing having a handle portion, a head portion and an end effector; a Raman spectroscopic probe encased in the housing and including: a laser disposed in the handle portion and operable to emit a coherent light beam; a laser line filter operable to transmit the light beam along an optical path and suppress ambient light; a beam splitter disposed in the head portion and operable to reflect the light beam from the laser line filter through an aperture formed in the end effector toward onto a sample to produce a Raman-shifted sample signal; a collector to collect the sample signal and transmit the sample signal through the beam splitter; a beam expander to collimate the sample signal from the beam splitter and generate an expanded diameter sample signal; an ultra-high resolution, narrow range, spatially graded filter to filter the expanded diameter sample signal in at least one narrow spectral band based on a predetermined set of discrete spectral bands for a target pathogen, wherein the filter is a band gap filter comprising graded indium aluminum nitride alloy; and an imager for converting the expanded diameter sample signal to image data representative of the Raman-shifted sample signal; and a laser disposed in the handle portion and operable to emit a coherent light beam; a laser line filter operable to transmit the light beam along an optical path and suppress ambient light; a beam splitter disposed in the head portion and operable to reflect the light beam from the laser line filter through an aperture formed in the end effector toward onto a sample to produce a Raman-shifted sample signal; a collector to collect the sample signal and transmit the sample signal through the beam splitter; a beam expander to collimate the sample signal from the beam splitter and generate an expanded diameter sample signal; an ultra-high resolution, narrow range, spatially graded filter to filter the expanded diameter sample signal in at least one narrow spectral band based on a predetermined set of discrete spectral bands for a target pathogen, wherein the filter is a band gap filter comprising graded indium aluminum nitride alloy; and an imager for converting the expanded diameter sample signal to image data representative of the Raman-shifted sample signal; and an electronics assembly including: a micro-controller encased within the housing for controlling the Raman spectroscopic probe, reading the image data from the imager, and analyzing the image data at the discrete spectral bands to detect the presence of the target pathogen, comparing the image data with a baseline Raman spectrum and communicating a test result based on the analysis and comparison; and a power source operably coupled to the micro-controller and the Raman spectroscopic probe. a micro-controller encased within the housing for controlling the Raman spectroscopic probe, reading the image data from the imager, and analyzing the image data at the discrete spectral bands to detect the presence of the target pathogen, comparing the image data with a baseline Raman spectrum and communicating a test result based on the analysis and comparison; and a power source operably coupled to the micro-controller and the Raman spectroscopic probe.