System including electromagnetic radiation source and electromagnetic radiation detector. Electromagnetic radiation source is configured to excite, with electromagnetic radiation having first source frequency, object configured for suppressing responsive emission of electromagnetic radiation having first source frequency. Electromagnetic radiation detector is configured to receive responsive emission of electromagnetic radiation from object. System is configured to detect presence of object. Method includes exciting, with electromagnetic radiation having first source frequency, object configured for suppressing responsive emission of electromagnetic radiation having first source frequency. Method includes receiving responsive emission of electromagnetic radiation from object and utilizing responsive emission to detect presence of object.