Abstract: Exemplary embodiments of apparatus according to the present disclosure are provided. For example, an apparatus for providing electromagnetic radiation to a structure can be provided. In one exemplary embodiment, the apparatus can provide at least one electromagnetic radiation, and include at least one first arrangement which can be configured to generate the electromagnetic radiation(s) having at least one wavelength that varies over time. The exemplary apparatus can also include at least one second arrangement which can be configured to power the first arrangement(s) independently from an external power source. In another exemplary embodiment the apparatus can include at least one particular arrangement which is configured to generate the electromagnetic radiation(s) having at least one wavelength that varies over time. The particular arrangement(s) can include a resonant cavity that has a roundtrip optical transit time of approximately less than 0.7 nsec.